Quiz about Chemistry in Class 12

Question 1

Read the given passage and answer the questions  Zero order reactions are relatively uncommon but they occur under special conditions. Some enzyme catalysed reactions and reactions which occurs on metal surfaces are a few examples of zero order reactions. The decompositions which occurs on metal surfaces are a few examples of zero order reactions. The decomposition of gaseous ammonia on a hot platinum surface is a zero order reaction at high pressure.  2NH_(3)(g) underset(Pt catalyst) overset(1130K)to N_(2)(g)+3H_(2)(g)  Rate=k[NH_(3)]^(0)=k  In this reaction Pt acts as a catalyst. At high pressure the metal surface gets saturated with gas molecules. So a further change in reaction conditions is unable to alter the amount of ammonia on the surface of the catalyst making the rate of the reaction independent of its concentration.  Q. Give another example of a zero order reaction.

Accepted Answer

NA

Question 2

Read the given passage and answer the questions Two solutions having same osmotic pressure at a given temperature are called isotonic solutions. When such solutions are separated by semipermeable membrane no osmosis occurs between them. For example the osmotic pressure associated with fluid inside the blood cell is equivalent to that of 0.9% (massvolume) sodium chloride solution called normal saline solution and it is safe to inject intravenously. On the other hand if we place the cells in a solution containing more than 0.9% sodium chloride water will flow out of the cells and they would shrink. Such a solution is called hypertonic. If the salt concentration is less than 0.9% the solution is said to be hypotonic. In this case water will flow into the cells if placed in this solution and they would swell. What is a hypotonic solution ?

Accepted Answer

NA

Question 3

Read the given passage and answer the questions Two solutions having same osmotic pressure at a given temperature are called isotonic solutions. When such solutions are separated by semipermeable membrane no osmosis occurs between them. For example the osmotic pressure associated with fluid inside the blood cell is equivalent to that of 0.9% (massvolume) sodium chloride solution called normal saline solution and it is safe to inject intravenously. On the other hand if we place the cells in a solution containing more than 0.9% sodium chloride water will flow out of the cells and they would shrink. Such a solution is called hypertonic. If the salt concentration is less than 0.9% the solution is said to be hypotonic. In this case water will flow into the cells if placed in this solution and they would swell.If a solution of 3 g of sodium chloride dissolved in 500 mL of water is injected into thebody what will happens to the blood cells ?

Accepted Answer

NA

Question 4

Read the given passage and answer the questions Two solutions having same osmotic pressure at a given temperature are called isotonic solutions. When such solutions are separated by semipermeable membrane no osmosis occurs between them. For example the osmotic pressure associated with fluid inside the blood cell is equivalent to that of 0.9% (massvolume) sodium chloride solution called normal saline solution and it is safe to inject intravenously. On the other hand if we place the cells in a solution containing more than 0.9% sodium chloride water will flow out of the cells and they would shrink. Such a solution is called hypertonic. If the salt concentration is less than 0.9% the solution is said to be hypotonic. In this case water will flow into the cells if placed in this solution and they would swell. Which concentration of sodium chloride solution is suitable for transfusion into blood ?

Accepted Answer

NA

Question 5

Read the given passage and answer the questions Two solutions having same osmotic pressure at a given temperature are called isotonic solutions. When such solutions are separated by semipermeable membrane no osmosis occurs between them. For example the osmotic pressure associated with fluid inside the blood cell is equivalent to that of 0.9% (massvolume) sodium chloride solution called normal saline solution and it is safe to inject intravenously. On the other hand if we place the cells in a solution containing more than 0.9% sodium chloride water will flow out of the cells and they would shrink. Such a solution is called hypertonic. If the salt concentration is less than 0.9% the solution is said to be hypotonic. In this case water will flow into the cells if placed in this solution and they would swell.What is a hypertonic solution ?

Accepted Answer

NA

Question 6

Read the given passage and answer the questions Two solutions having same osmotic pressure at a given temperature are called isotonic solutions. When such solutions are separated by semipermeable membrane no osmosis occurs between them. For example the osmotic pressure associated with fluid inside the blood cell is equivalent to that of 0.9% (massvolume) sodium chloride solution called normal saline solution and it is safe to inject intravenously. On the other hand if we place the cells in a solution containing more than 0.9% sodium chloride water will flow out of the cells and they would shrink. Such a solution is called hypertonic. If the salt concentration is less than 0.9% the solution is said to be hypotonic. In this case water will flow into the cells if placed in this solution and they would swell. What is meant by isotonic solutions ?

Accepted Answer

NA

Question 7

Read the given passage and answer the questions The substitution reaction of alkyl halide mainly occurs by S_(N)1 or S_(N)2 mechanism. Whatever mechanism alkyl halides follow for the substitution reactionto occur the polarity of the carbon hallogen bond is responsible for these substitution reactions. The rates of S_(N)1 reactions are governed by the stability of carbocation whereas for S_(N)2 reactions steric factor is the deciding factor. If the starting material is a chiral compound we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI is also governed by steric factor and stability of carbocation which indicates that in organic chemistry these two major factors help us in deciding the kind of product formed.  Q. Name the instrument used for measuring the angle by which the plane polarised light is rotated.

Accepted Answer

NA

Question 8

Read the given passage and answer the questions The substitution reaction of alkyl halide mainly occurs by S_(N)1 or S_(N)2 mechanism. Whatever mechanism alkyl halides follow for the substitution reactionto occur the polarity of the carbon hallogen bond is responsible for these substitution reactions. The rates of S_(N)1 reactions are governed by the stability of carbocation whereas for S_(N)2 reactions steric factor is the deciding factor. If the starting material is a chiral compound we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI is also governed by steric factor and stability of carbocation which indicates that in organic chemistry these two major factors help us in deciding the kind of product formed.  Q. Give one use of CHI_(3).

Accepted Answer

NA

Question 9

Read the given passage and answer the questions The substitution reaction of alkyl halide mainly occurs by S_(N)1 or S_(N)2 mechanism. Whatever mechanism alkyl halides follow for the substitution reactionto occur the polarity of the carbon hallogen bond is responsible for these substitution reactions. The rates of S_(N)1 reactions are governed by the stability of carbocation whereas for S_(N)2 reactions steric factor is the deciding factor. If the starting material is a chiral compound we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI is also governed by steric factor and stability of carbocation which indicates that in organic chemistry these two major factors help us in deciding the kind of product formed.  Q. Predict the stereochemistry of the product formed if an optically active alkyl halide undergoes substitution by S_(N)2 mechanism.

Accepted Answer

NA

Question 10

Read the given passage and answer the questions The substitution reaction of alkyl halide mainly occurs by S_(N)1 or S_(N)2 mechanism. Whatever mechanism alkyl halides follow for the substitution reactionto occur the polarity of the carbon hallogen bond is responsible for these substitution reactions. The rates of S_(N)1 reactions are governed by the stability of carbocation whereas for S_(N)2 reactions steric factor is the deciding factor. If the starting material is a chiral compound we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI is also governed by steric factor and stability of carbocation which indicates that in organic chemistry these two major factors help us in deciding the kind of product formed.  Q. Predict the major product formed when 2-Bromobutane undergoes a reaction with alcoholic KOH.

Accepted Answer

NA

Question 11

Read the given passage and answer the questions The substitution reaction of alkyl halide mainly occurs by S_(N)1 or S_(N)2 mechanism. Whatever mechanism alkyl halides follow for the substitution reactionto occur the polarity of the carbon hallogen bond is responsible for these substitution reactions. The rates of S_(N)1 reactions are governed by the stability of carbocation whereas for S_(N)2 reactions steric factor is the deciding factor. If the starting material is a chiral compound we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI is also governed by steric factor and stability of carbocation which indicates that in organic chemistry these two major factors help us in deciding the kind of product formed.  Q. Write the structures of the products formed when anisole is treated with HI.

Accepted Answer

NA

Question 12

Read the given passage and answer the questionsThe direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is now the pure solvent flows out of the solution through the semi permeable membrane. This phenomenon is called reverse osmosis and is of great practical utility. Reverse osmosis is used in the desalination of sea water. When pressure more than the osmotic pressure is applied pure water is squeezed out of sea water through the membrane. A variety of polymer membranes are available for this purpose.Give one example of a material used in the preparation of membrane.

Accepted Answer

NA

Question 13

Read the given passage and answer the questionsThe direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is now the pure solvent flows out of the solution through the semi permeable membrane. This phenomenon is called reverse osmosis and is of great practical utility. Reverse osmosis is used in the desalination of sea water. When pressure more than the osmotic pressure is applied pure water is squeezed out of sea water through the membrane. A variety of polymer membranes are available for this purpose.Give one more example of osmosis in daily use.

Accepted Answer

NA

Question 14

Read the given passage and answer the questionsThe direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is now the pure solvent flows out of the solution through the semi permeable membrane. This phenomenon is called reverse osmosis and is of great practical utility. Reverse osmosis is used in the desalination of sea water. When pressure more than the osmotic pressure is applied pure water is squeezed out of sea water through the membrane. A variety of polymer membranes are available for this purpose.What is the function of membrane in reverse osmosis ?

Accepted Answer

NA

Question 15

Read the given passage and answer the questions that follow  The anomalous behaviour of oxygen like other members of p-block present in second period is due to its small size and high electronegativity. One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H_2O which is not found in H_2S. The absence of d-orbitals in oxygen limits its covalency to four and in practice rarely exceeds two. On the other hand in case of other elements of the group the valence shells can be expanded and covalence exceeds four. How can we expand the valency shell in the case of elements lying lower in the group of oxygen ?

Accepted Answer

NA

Question 16

Read the given passage and answer the questions that follow  The anomalous behaviour of oxygen like other members of p-block present in second period is due to its small size and high electronegativity. One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H_2O which is not found in H_2S. The absence of d-orbitals in oxygen limits its covalency to four and in practice rarely exceeds two. On the other hand in case of other elements of the group the valence shells can be expanded and covalence exceeds four. Name the fifth member of the group of oxygen.

Accepted Answer

NA

Question 17

Read the given passage and answer the questionsThe direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is now the pure solvent flows out of the solution through the semi permeable membrane. This phenomenon is called reverse osmosis and is of great practical utility. Reverse osmosis is used in the desalination of sea water. When pressure more than the osmotic pressure is applied pure water is squeezed out of sea water through the membrane. A variety of polymer membranes are available for this purpose.Give one utility of reverse osmosis.

Accepted Answer

NA

Question 18

Read the given passage and answer the questionsThe direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is now the pure solvent flows out of the solution through the semi permeable membrane. This phenomenon is called reverse osmosis and is of great practical utility. Reverse osmosis is used in the desalination of sea water. When pressure more than the osmotic pressure is applied pure water is squeezed out of sea water through the membrane. A variety of polymer membranes are available for this purpose.What is meant by reverse osmosis ?

Accepted Answer

NA

Question 19

Read the given passage and answer the questions that follow  The anomalous behaviour of oxygen like other members of p-block present in second period is due to its small size and high electronegativity. One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H_2O which is not found in H_2S. The absence of d-orbitals in oxygen limits its covalency to four and in practice rarely exceeds two. On the other hand in case of other elements of the group the valence shells can be expanded and covalence exceeds four. H_2O is a water at room temperature whereas H_2S is a gas.

Accepted Answer

NA

Question 20

Read the given passage and answer the questionsthat follow  Surface chemistry deals with the phenomena that occur at the surfaces or interfaces. The interface or surface is represented by separating the bulk phases by a hyphen or a slash. For example the interface between a solid and a gas may be represented by solid-gas or solidgas. Due to complete miscibility there is no interface between the gases. The bulk phases that we come across in surface chemistry may be pure compounds or solutions. The interface is normally a few molecules thick but its area depends on the size of the particles of bulk phases. Many important phenomena noticeable among these being corrosion electrode processes heterogeneous catalysis dissolution and crystallisation occur at interfaces. The subject of surface chemistry finds many applications in industry analytical work and daily life situations.  Which phenomena are studied under surface chemistry ?

Accepted Answer

NA

Question 21

Read the given passage and answer the questions that follow  The anomalous behaviour of oxygen like other members of p-block present in second period is due to its small size and high electronegativity. One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H_2O which is not found in H_2S. The absence of d-orbitals in oxygen limits its covalency to four and in practice rarely exceeds two. On the other hand in case of other elements of the group the valence shells can be expanded and covalence exceeds four.First element of the groups in p-block shows anomalous behaviour from other elements of the group. Explain.

Accepted Answer

NA

Question 22

Read the given passage and answer the questionsthat follow  Surface chemistry deals with the phenomena that occur at the surfaces or interfaces. The interface or surface is represented by separating the bulk phases by a hyphen or a slash. For example the interface between a solid and a gas may be represented by solid-gas or solidgas. Due to complete miscibility there is no interface between the gases. The bulk phases that we come across in surface chemistry may be pure compounds or solutions. The interface is normally a few molecules thick but its area depends on the size of the particles of bulk phases. Many important phenomena noticeable among these being corrosion electrode processes heterogeneous catalysis dissolution and crystallisation occur at interfaces. The subject of surface chemistry finds many applications in industry analytical work and daily life situations.  Which out of adsorption catalysis and colloids is studied under surface chemistry ?

Accepted Answer

NA

Question 23

Read the given passage and answer the questions that follow  The anomalous behaviour of oxygen like other members of p-block present in second period is due to its small size and high electronegativity. One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H_2O which is not found in H_2S. The absence of d-orbitals in oxygen limits its covalency to four and in practice rarely exceeds two. On the other hand in case of other elements of the group the valence shells can be expanded and covalence exceeds four. Give the names of third and fourth members of the group to which O and S belong.

Accepted Answer

NA

Question 24

Read the given passage and answer the questionsthat follow  Surface chemistry deals with the phenomena that occur at the surfaces or interfaces. The interface or surface is represented by separating the bulk phases by a hyphen or a slash. For example the interface between a solid and a gas may be represented by solid-gas or solidgas. Due to complete miscibility there is no interface between the gases. The bulk phases that we come across in surface chemistry may be pure compounds or solutions. The interface is normally a few molecules thick but its area depends on the size of the particles of bulk phases. Many important phenomena noticeable among these being corrosion electrode processes heterogeneous catalysis dissolution and crystallisation occur at interfaces. The subject of surface chemistry finds many applications in industry analytical work and daily life situations. How do you define surface chemistry?

Accepted Answer

NA

Question 25

Read the given passage and answer the questionsthat follow  Surface chemistry deals with the phenomena that occur at the surfaces or interfaces. The interface or surface is represented by separating the bulk phases by a hyphen or a slash. For example the interface between a solid and a gas may be represented by solid-gas or solidgas. Due to complete miscibility there is no interface between the gases. The bulk phases that we come across in surface chemistry may be pure compounds or solutions. The interface is normally a few molecules thick but its area depends on the size of the particles of bulk phases. Many important phenomena noticeable among these being corrosion electrode processes heterogeneous catalysis dissolution and crystallisation occur at interfaces. The subject of surface chemistry finds many applications in industry analytical work and daily life situations.  What are the dimensions of the interface and its surface area ?

Accepted Answer

NA

Question 26

Read the given passage and answer the questionsthat follow  Surface chemistry deals with the phenomena that occur at the surfaces or interfaces. The interface or surface is represented by separating the bulk phases by a hyphen or a slash. For example the interface between a solid and a gas may be represented by solid-gas or solidgas. Due to complete miscibility there is no interface between the gases. The bulk phases that we come across in surface chemistry may be pure compounds or solutions. The interface is normally a few molecules thick but its area depends on the size of the particles of bulk phases. Many important phenomena noticeable among these being corrosion electrode processes heterogeneous catalysis dissolution and crystallisation occur at interfaces. The subject of surface chemistry finds many applications in industry analytical work and daily life situations. Can oxygenhydrogen form interface ?

Accepted Answer

NA

Question 27

Read the given passage and answer the questions that follow  Potassium chlorate when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of 653-873 K.  2KClO_3 overset(Heat)to 2KCl + 3O_2  However when a little of manganese dioxide is added the decomposition takes place at a considerably lower temperature range i.e. 473-633 K and also at a much accelerated rate. The added manganese dioxide remains unchanged with respect to its mass and composition. In a similar manner the rates of a number of a chemical reactions can be altered by the mere presence of a foreign substance.  The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius in 1835. He suggested the term catalyst for such substances. Give another example of a reaction and the catalyst used in the reaction.

Accepted Answer

NA

Question 28

Read the given passage and answer the questions that follow  Potassium chlorate when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of 653-873 K.  2KClO_3 overset(Heat)to 2KCl + 3O_2  However when a little of manganese dioxide is added the decomposition takes place at a considerably lower temperature range i.e. 473-633 K and also at a much accelerated rate. The added manganese dioxide remains unchanged with respect to its mass and composition. In a similar manner the rates of a number of a chemical reactions can be altered by the mere presence of a foreign substance.  The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius in 1835. He suggested the term catalyst for such substances. How the catalyst is able to lower down the temperature of reaction ?

Accepted Answer

NA

Question 29

Read the given passage and answer the questions that follow  Potassium chlorate when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of 653-873 K.  2KClO_3 overset(Heat)to 2KCl + 3O_2  However when a little of manganese dioxide is added the decomposition takes place at a considerably lower temperature range i.e. 473-633 K and also at a much accelerated rate. The added manganese dioxide remains unchanged with respect to its mass and composition. In a similar manner the rates of a number of a chemical reactions can be altered by the mere presence of a foreign substance.  The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius in 1835. He suggested the term catalyst for such substances. What happens to the catalyst after reactions ?

Accepted Answer

NA

Question 30

Read the given passage and answer the questions that follow  Potassium chlorate when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of 653-873 K.  2KClO_3 overset(Heat)to 2KCl + 3O_2  However when a little of manganese dioxide is added the decomposition takes place at a considerably lower temperature range i.e. 473-633 K and also at a much accelerated rate. The added manganese dioxide remains unchanged with respect to its mass and composition. In a similar manner the rates of a number of a chemical reactions can be altered by the mere presence of a foreign substance.  The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius in 1835. He suggested the term catalyst for such substances. Who made a systematic study of the effect of foreign substances on the rates of chemical reactions and when ?

Accepted Answer

NA

Question 31

Read the given passage and answer the questions that follow  Potassium chlorate when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of 653-873 K.  2KClO_3 overset(Heat)to 2KCl + 3O_2  However when a little of manganese dioxide is added the decomposition takes place at a considerably lower temperature range i.e. 473-633 K and also at a much accelerated rate. The added manganese dioxide remains unchanged with respect to its mass and composition. In a similar manner the rates of a number of a chemical reactions can be altered by the mere presence of a foreign substance.  The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius in 1835. He suggested the term catalyst for such substances. What is the utility of catalysts?

Accepted Answer

NA

Question 32

Read the given passage and answer the questions that follow  Molecular nitrogen comprises 78% by volume of the atmosphere. In the earths crust it occurs as sodium nitrate NaNO_3 (called Chile saltpetre) and potassium nitrate (Indian saltpetre). It is found in the form of proteins in plants and animals. Phosphorus occurs in minerals of the apatite family Ca_(9)(PO_4)_6. CaX_2 ( X=FCl or OH)(for example fluorapatite Ca_9(PO_4)_6. CaF_2) which are the main components of phosphate rocks. Phosphorus is an essential constituent of animal and plant matter. It is present in bones as well as in living cells. Phosphoproteins are present in milk and eggs. Arsenic antimony and bismuth are found mainly as sulphide minerals. Moscovium is a synthetic radioactive element. Its symbol is Mc atomic number 115 atomic mass 289 and electronic configuration [Rn]5f^(15) 6d^(10)7s^(2)7p^(3).  Give the names of third fourth and fifth members of nitrogen family.

Accepted Answer

NA

Question 33

Read the given passage and answer the questions that follow  Molecular nitrogen comprises 78% by volume of the atmosphere. In the earths crust it occurs as sodium nitrate NaNO_3 (called Chile saltpetre) and potassium nitrate (Indian saltpetre). It is found in the form of proteins in plants and animals. Phosphorus occurs in minerals of the apatite family Ca_(9)(PO_4)_6. CaX_2 ( X=FCl or OH)(for example fluorapatite Ca_9(PO_4)_6. CaF_2) which are the main components of phosphate rocks. Phosphorus is an essential constituent of animal and plant matter. It is present in bones as well as in living cells. Phosphoproteins are present in milk and eggs. Arsenic antimony and bismuth are found mainly as sulphide minerals. Moscovium is a synthetic radioactive element. Its symbol is Mc atomic number 115 atomic mass 289 and electronic configuration [Rn]5f^(15) 6d^(10)7s^(2)7p^(3).  Give the electronic configuration of Moscovium.

Accepted Answer

NA

Question 34

Read the given passage and answer the questions that follow  Molecular nitrogen comprises 78% by volume of the atmosphere. In the earths crust it occurs as sodium nitrate NaNO_3 (called Chile saltpetre) and potassium nitrate (Indian saltpetre). It is found in the form of proteins in plants and animals. Phosphorus occurs in minerals of the apatite family Ca_(9)(PO_4)_6. CaX_2 ( X=FCl or OH)(for example fluorapatite Ca_9(PO_4)_6. CaF_2) which are the main components of phosphate rocks. Phosphorus is an essential constituent of animal and plant matter. It is present in bones as well as in living cells. Phosphoproteins are present in milk and eggs. Arsenic antimony and bismuth are found mainly as sulphide minerals. Moscovium is a synthetic radioactive element. Its symbol is Mc atomic number 115 atomic mass 289 and electronic configuration [Rn]5f^(15) 6d^(10)7s^(2)7p^(3).  What is the composition of apatite family compounds ?

Accepted Answer

NA

Question 35

Read the given passage and answer the questions that follow  Molecular nitrogen comprises 78% by volume of the atmosphere. In the earths crust it occurs as sodium nitrate NaNO_3 (called Chile saltpetre) and potassium nitrate (Indian saltpetre). It is found in the form of proteins in plants and animals. Phosphorus occurs in minerals of the apatite family Ca_(9)(PO_4)_6. CaX_2 ( X=FCl or OH)(for example fluorapatite Ca_9(PO_4)_6. CaF_2) which are the main components of phosphate rocks. Phosphorus is an essential constituent of animal and plant matter. It is present in bones as well as in living cells. Phosphoproteins are present in milk and eggs. Arsenic antimony and bismuth are found mainly as sulphide minerals. Moscovium is a synthetic radioactive element. Its symbol is Mc atomic number 115 atomic mass 289 and electronic configuration [Rn]5f^(15) 6d^(10)7s^(2)7p^(3).  Name the natural substances that contain phosphorus.

Accepted Answer

NA

Question 36

Read the given passage and answer the questions that follow  Molecular nitrogen comprises 78% by volume of the atmosphere. In the earths crust it occurs as sodium nitrate NaNO_3 (called Chile saltpetre) and potassium nitrate (Indian saltpetre). It is found in the form of proteins in plants and animals. Phosphorus occurs in minerals of the apatite family Ca_(9)(PO_4)_6. CaX_2 ( X=FCl or OH)(for example fluorapatite Ca_9(PO_4)_6. CaF_2) which are the main components of phosphate rocks. Phosphorus is an essential constituent of animal and plant matter. It is present in bones as well as in living cells. Phosphoproteins are present in milk and eggs. Arsenic antimony and bismuth are found mainly as sulphide minerals. Moscovium is a synthetic radioactive element. Its symbol is Mc atomic number 115 atomic mass 289 and electronic configuration [Rn]5f^(15) 6d^(10)7s^(2)7p^(3).  What is the difference between Indian saltpetre and Chile saltpetre?

Accepted Answer

NA

Question 37

Read the given passage and answer the questions that follow  In adsorption the substance is concentrated only at the surface and does not penetrate through the surface to the bulk of the adsorbent while in absorption the substance is uniformly distributed throughout the bulk of the solid. For example when a chalk stick is dipped in ink the surface retains the colour of the ink due to adsorption of coloured molecules while the solvent of the ink goes deeper into the stick due to absorption. On breaking the chalk stick it is found to be white from inside. A distinction can be made between absorption and adsorption by taking an example of water vapour. Water vapours are absorbed by anhydrous calcium chloride but adsorbed by silica gel. In other words in adsorption the concentration of the adsorbate increases only at the surface of the adsorbent while in adsorption the concentration is uniform throughout the bulk of the solid. Can you cite an example where adsorption and absorption take place ?

Accepted Answer

NA

Question 38

Read the given passage and answer the questions that follow  “In the early years of independence two contradictory tendencies were already well advanced inside the Congress Party. On the other hand the national party executive endorsed socialist principles of state ownership regulation and control over key sectors of the economy in order to improve productivity and at the same time curb economic concentration. On the other hand the national Congress government pursued liberal economic policies and incentives to private investment that was justified in terms of sole criterion of achieving maximum increase in production”.  Francine Frankel  a) What concept of planning was finally adopted by India ?  b) In order to improve productivity which principles were endorsed by the national party.  c) Do you agree - that there was a contradiction between the central leadership of the Congress party and its state level leaders. Justify your answer

Accepted Answer

NA

Question 39

Read the given passage and answer the questions that follow  In adsorption the substance is concentrated only at the surface and does not penetrate through the surface to the bulk of the adsorbent while in absorption the substance is uniformly distributed throughout the bulk of the solid. For example when a chalk stick is dipped in ink the surface retains the colour of the ink due to adsorption of coloured molecules while the solvent of the ink goes deeper into the stick due to absorption. On breaking the chalk stick it is found to be white from inside. A distinction can be made between absorption and adsorption by taking an example of water vapour. Water vapours are absorbed by anhydrous calcium chloride but adsorbed by silica gel. In other words in adsorption the concentration of the adsorbate increases only at the surface of the adsorbent while in adsorption the concentration is uniform throughout the bulk of the solid. What is the term used when both adsorption and absorption occur ?

Accepted Answer

NA

Question 40

Read the given passage and answer the questions that follow  In adsorption the substance is concentrated only at the surface and does not penetrate through the surface to the bulk of the adsorbent while in absorption the substance is uniformly distributed throughout the bulk of the solid. For example when a chalk stick is dipped in ink the surface retains the colour of the ink due to adsorption of coloured molecules while the solvent of the ink goes deeper into the stick due to absorption. On breaking the chalk stick it is found to be white from inside. A distinction can be made between absorption and adsorption by taking an example of water vapour. Water vapours are absorbed by anhydrous calcium chloride but adsorbed by silica gel. In other words in adsorption the concentration of the adsorbate increases only at the surface of the adsorbent while in adsorption the concentration is uniform throughout the bulk of the solid.Give one example of a substance which shows adsorption and one example of a substance which shows absorption.

Accepted Answer

NA

Question 41

Read the given passage and answer the questions that follow  In adsorption the substance is concentrated only at the surface and does not penetrate through the surface to the bulk of the adsorbent while in absorption the substance is uniformly distributed throughout the bulk of the solid. For example when a chalk stick is dipped in ink the surface retains the colour of the ink due to adsorption of coloured molecules while the solvent of the ink goes deeper into the stick due to absorption. On breaking the chalk stick it is found to be white from inside. A distinction can be made between absorption and adsorption by taking an example of water vapour. Water vapours are absorbed by anhydrous calcium chloride but adsorbed by silica gel. In other words in adsorption the concentration of the adsorbate increases only at the surface of the adsorbent while in adsorption the concentration is uniform throughout the bulk of the solid. A substance when placed in a solution reveals that the solution has made the whole of the substance wet. What kind of phenomenon is this?

Accepted Answer

NA

Question 42

Read the given passage and answer the questions that follow  In adsorption the substance is concentrated only at the surface and does not penetrate through the surface to the bulk of the adsorbent while in absorption the substance is uniformly distributed throughout the bulk of the solid. For example when a chalk stick is dipped in ink the surface retains the colour of the ink due to adsorption of coloured molecules while the solvent of the ink goes deeper into the stick due to absorption. On breaking the chalk stick it is found to be white from inside. A distinction can be made between absorption and adsorption by taking an example of water vapour. Water vapours are absorbed by anhydrous calcium chloride but adsorbed by silica gel. In other words in adsorption the concentration of the adsorbate increases only at the surface of the adsorbent while in adsorption the concentration is uniform throughout the bulk of the solid. What is adsorption ?

Accepted Answer

NA

Question 43

Read the given passage and answer the questionsthat follow  Fluorine and chlorine are fairly abundant while bromine and iodine less so. Fluorine is present mainly as insoluble fluorides [fluorspar CaF_2 crylolite Na_3AlF_6 and fluoroapatite 3Ca_3(PO_4)2. CaF2] and small quantities are present in soil river water plants and bones and teeth of animals. Sea water contains chlorides bromides and iodides of sodium potassium magnesium and calcium but is mainly sodium chloride solution (2.5% by mass). The deposits of dried up seas contain these compounds for example sodium chloride and carnalliteKCl.MgCl_2.6H_2O. Certain forms of marine life contain iodine in their systems various seaweeds for example contain upto 0.5% of iodine and Chile saltpetre contains upto 0.2% of sodium iodate. Tennessine is a synthetic radioactive element. Its symbol is Ts atomic number 117 atomic mass 294 and electronic configuration [Rn]5f^(14) 6d^(10) 7s^(2) 7p^(5). Name the last element of Group 17 its atomic mass and electronic configuration.

Accepted Answer

NA

Question 44

Read the given passage and answer the questionsthat follow  Fluorine and chlorine are fairly abundant while bromine and iodine less so. Fluorine is present mainly as insoluble fluorides [fluorspar CaF_2 crylolite Na_3AlF_6 and fluoroapatite 3Ca_3(PO_4)2. CaF2] and small quantities are present in soil river water plants and bones and teeth of animals. Sea water contains chlorides bromides and iodides of sodium potassium magnesium and calcium but is mainly sodium chloride solution (2.5% by mass). The deposits of dried up seas contain these compounds for example sodium chloride and carnalliteKCl.MgCl_2.6H_2O. Certain forms of marine life contain iodine in their systems various seaweeds for example contain upto 0.5% of iodine and Chile saltpetre contains upto 0.2% of sodium iodate. Tennessine is a synthetic radioactive element. Its symbol is Ts atomic number 117 atomic mass 294 and electronic configuration [Rn]5f^(14) 6d^(10) 7s^(2) 7p^(5). Write the formula of fluorapatite.

Accepted Answer

NA

Question 45

Read the given passage and answer the questionsthat follow  Fluorine and chlorine are fairly abundant while bromine and iodine less so. Fluorine is present mainly as insoluble fluorides [fluorspar CaF_2 crylolite Na_3AlF_6 and fluoroapatite 3Ca_3(PO_4)2. CaF2] and small quantities are present in soil river water plants and bones and teeth of animals. Sea water contains chlorides bromides and iodides of sodium potassium magnesium and calcium but is mainly sodium chloride solution (2.5% by mass). The deposits of dried up seas contain these compounds for example sodium chloride and carnalliteKCl.MgCl_2.6H_2O. Certain forms of marine life contain iodine in their systems various seaweeds for example contain upto 0.5% of iodine and Chile saltpetre contains upto 0.2% of sodium iodate. Tennessine is a synthetic radioactive element. Its symbol is Ts atomic number 117 atomic mass 294 and electronic configuration [Rn]5f^(14) 6d^(10) 7s^(2) 7p^(5).Name the elements of Group 17 of the Periodic Table.

Accepted Answer

NA

Question 46

Read the given passage and answer the questions numberthat follow  Weak electrolytes like acetic acid have lower degree of dissociation at higher concentrations and hence for such electrolytes the change in Lambda_(m)with dilution is due to increase in the degree of dissociation and consequently the number of ions in total volume of solution that contains one mol of electrolyte. In such cases Lambda_(m)increases steeply on dilution especially near lower concentrations. Therefore Lambda_(m)cannot be obtained by extrapolation of Lambda_(m)to zero concentration. At infinite dilution (i.e. concentration c tozero) electrolyte dissociates completely (alpha= 1) but at such low concentration the conductivity of the solution is so low that it cannot be measured accurately. Therefore Lambda_(m)^(@)for weak electrolytes is obtained by using Kohlrausch law of independence migration of ions. Give the mathematical relation to calculate the degree of dissociation alphafor a weak electrolyte.

Accepted Answer

NA

Question 47

Read the given passage and answer the questionsthat follow  Fluorine and chlorine are fairly abundant while bromine and iodine less so. Fluorine is present mainly as insoluble fluorides [fluorspar CaF_2 crylolite Na_3AlF_6 and fluoroapatite 3Ca_3(PO_4)2. CaF2] and small quantities are present in soil river water plants and bones and teeth of animals. Sea water contains chlorides bromides and iodides of sodium potassium magnesium and calcium but is mainly sodium chloride solution (2.5% by mass). The deposits of dried up seas contain these compounds for example sodium chloride and carnalliteKCl.MgCl_2.6H_2O. Certain forms of marine life contain iodine in their systems various seaweeds for example contain upto 0.5% of iodine and Chile saltpetre contains upto 0.2% of sodium iodate. Tennessine is a synthetic radioactive element. Its symbol is Ts atomic number 117 atomic mass 294 and electronic configuration [Rn]5f^(14) 6d^(10) 7s^(2) 7p^(5). Name the main substances in the deposits of dried up seas.

Accepted Answer

NA

Question 48

Read the given passage and answer the questions numberthat follow  Weak electrolytes like acetic acid have lower degree of dissociation at higher concentrations and hence for such electrolytes the change in Lambda_(m)with dilution is due to increase in the degree of dissociation and consequently the number of ions in total volume of solution that contains one mol of electrolyte. In such cases Lambda_(m)increases steeply on dilution especially near lower concentrations. Therefore Lambda_(m)cannot be obtained by extrapolation of Lambda_(m)to zero concentration. At infinite dilution (i.e. concentration c tozero) electrolyte dissociates completely (alpha= 1) but at such low concentration the conductivity of the solution is so low that it cannot be measured accurately. Therefore Lambda_(m)^(@)for weak electrolytes is obtained by using Kohlrausch law of independence migration of ions. Which law is used lo calculate Lambda_(m)^(@)for weak electrolyles ?

Accepted Answer

NA

Question 49

Read the given passage and answer the questions numberthat follow  Weak electrolytes like acetic acid have lower degree of dissociation at higher concentrations and hence for such electrolytes the change in Lambda_(m)with dilution is due to increase in the degree of dissociation and consequently the number of ions in total volume of solution that contains one mol of electrolyte. In such cases Lambda_(m)increases steeply on dilution especially near lower concentrations. Therefore Lambda_(m)cannot be obtained by extrapolation of Lambda_(m)to zero concentration. At infinite dilution (i.e. concentration c tozero) electrolyte dissociates completely (alpha= 1) but at such low concentration the conductivity of the solution is so low that it cannot be measured accurately. Therefore Lambda_(m)^(@)for weak electrolytes is obtained by using Kohlrausch law of independence migration of ions.  Why cant we obtain Lambda_(m)^(@)by extrapolation of Lambda_(m)to zero concentration ?

Accepted Answer

NA

Question 50

Read the given passage and answer the questions numberthat follow  Weak electrolytes like acetic acid have lower degree of dissociation at higher concentrations and hence for such electrolytes the change in Lambda_(m)with dilution is due to increase in the degree of dissociation and consequently the number of ions in total volume of solution that contains one mol of electrolyte. In such cases Lambda_(m)increases steeply on dilution especially near lower concentrations. Therefore Lambda_(m)cannot be obtained by extrapolation of Lambda_(m)to zero concentration. At infinite dilution (i.e. concentration c tozero) electrolyte dissociates completely (alpha= 1) but at such low concentration the conductivity of the solution is so low that it cannot be measured accurately. Therefore Lambda_(m)^(@)for weak electrolytes is obtained by using Kohlrausch law of independence migration of ions. Why does the change in Lambda_(m) take place on dilution in case of weak electrolytes ?

Accepted Answer

NA

1.	Read the given passage and answer the questions: Zero order reactions are relatively uncommon but they occur under special conditions. Some enzyme catalysed reactions and reactions which occurs on metal surfaces are a few examples of zero order reactions. The decompositions which occurs on metal surfaces are a few examples of zero order reactions. The decomposition of gaseous ammonia on a hot platinum surface is a zero order reaction at high pressure. 2NH_(3)(g) underset("Pt catalyst") overset(1130K)to N_(2)(g)+3H_(2)(g) Rate=k[NH_(3)]^(0)=k In this reaction, Pt acts as a catalyst. At high pressure, the metal surface gets saturated with gas molecules. So a further change in reaction conditions is unable to alter the amount of ammonia on the surface of the catalyst making the rate of the reaction independent of its concentration. Q. Give another example of a zero order reaction.
Answer» Solution :Thermal decompositionof HI on GOLD SURFACE.

2.	Read the given passage and answer the questions : Two solutions having same osmotic pressure at a given temperature are called isotonic solutions. When such solutions are separated by semipermeable membrane, no osmosis occurs between them. For example, the osmotic pressure associated with fluid inside the blood cell is equivalent to that of 0.9% (mass/volume) sodium chloride solution, called normal saline solution and it is safe to inject intravenously. On the other hand, if we place the cells in a solution containing more than 0.9% sodium chloride, water will flow out of the cells and they would shrink. Such a solution is called hypertonic. If the salt concentration is less than 0.9%, the solution is said to be hypotonic. In this case, water will flow into the cells if placed in this solution and they would swell. What is a hypotonic solution ?
Answer» SOLUTION :If the osomotic PRESSURE of a solution is LOWER than that of ANOTHER solution, the formersolution is HYPOTONIC solution.

3.	Read the given passage and answer the questions : Two solutions having same osmotic pressure at a given temperature are called isotonic solutions. When such solutions are separated by semipermeable membrane, no osmosis occurs between them. For example, the osmotic pressure associated with fluid inside the blood cell is equivalent to that of 0.9% (mass/volume) sodium chloride solution, called normal saline solution and it is safe to inject intravenously. On the other hand, if we place the cells in a solution containing more than 0.9% sodium chloride, water will flow out of the cells and they would shrink. Such a solution is called hypertonic. If the salt concentration is less than 0.9%, the solution is said to be hypotonic. In this case, water will flow into the cells if placed in this solution and they would swell.If a solution of 3 g of sodium chloride dissolved in 500 mL of water is injected into thebody, what will happens to the blood cells ?
Answer» SOLUTION : The concentration of this solution is 0.6 G per 100 mL or 0.6%. Hence, water will flow intothe cells and they WOULD BURST.

4.	Read the given passage and answer the questions : Two solutions having same osmotic pressure at a given temperature are called isotonic solutions. When such solutions are separated by semipermeable membrane, no osmosis occurs between them. For example, the osmotic pressure associated with fluid inside the blood cell is equivalent to that of 0.9% (mass/volume) sodium chloride solution, called normal saline solution and it is safe to inject intravenously. On the other hand, if we place the cells in a solution containing more than 0.9% sodium chloride, water will flow out of the cells and they would shrink. Such a solution is called hypertonic. If the salt concentration is less than 0.9%, the solution is said to be hypotonic. In this case, water will flow into the cells if placed in this solution and they would swell. Which concentration of sodium chloride solution is suitable for transfusion into blood ?
Answer» SOLUTION : 0.9/100 ML solution of SODIUM chloride in WATER is suitable for transfusion into BLOOD.

5.	Read the given passage and answer the questions : Two solutions having same osmotic pressure at a given temperature are called isotonic solutions. When such solutions are separated by semipermeable membrane, no osmosis occurs between them. For example, the osmotic pressure associated with fluid inside the blood cell is equivalent to that of 0.9% (mass/volume) sodium chloride solution, called normal saline solution and it is safe to inject intravenously. On the other hand, if we place the cells in a solution containing more than 0.9% sodium chloride, water will flow out of the cells and they would shrink. Such a solution is called hypertonic. If the salt concentration is less than 0.9%, the solution is said to be hypotonic. In this case, water will flow into the cells if placed in this solution and they would swell.What is a hypertonic solution ?
Answer» SOLUTION : If the osmotic pressure of a solution is higher than that of ANOTHER solution, the FORMER solution is HYPERTONIC solution.

6.	Read the given passage and answer the questions : Two solutions having same osmotic pressure at a given temperature are called isotonic solutions. When such solutions are separated by semipermeable membrane, no osmosis occurs between them. For example, the osmotic pressure associated with fluid inside the blood cell is equivalent to that of 0.9% (mass/volume) sodium chloride solution, called normal saline solution and it is safe to inject intravenously. On the other hand, if we place the cells in a solution containing more than 0.9% sodium chloride, water will flow out of the cells and they would shrink. Such a solution is called hypertonic. If the salt concentration is less than 0.9%, the solution is said to be hypotonic. In this case, water will flow into the cells if placed in this solution and they would swell. What is meant by isotonic solutions ?
Answer» Solution :Two SOLUTIONS having the same osmotic PRESSURE are called isotonic solutions.

7.	Read the given passage and answer the questions The substitution reaction of alkyl halide mainly occurs by S_(N)1 or S_(N)2 mechanism. Whatever mechanism alkyl halides follow for the substitution reactionto occur, the polarity of the carbon hallogen bond is responsible for these substitution reactions. The rates of S_(N)1 reactions are governed by the stability of carbocation whereas for S_(N)2 reactions steric factor is the deciding factor. If the starting material is a chiral compound, we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI is also governed by steric factor and stability of carbocation, which indicates that in organic chemistry, these two major factors help us in deciding the kind of product formed. Q. Name the instrument used for measuring the angle by which the plane, polarised light is rotated.
Answer» SOLUTION :POLARIMETER.

8.	Read the given passage and answer the questions The substitution reaction of alkyl halide mainly occurs by S_(N)1 or S_(N)2 mechanism. Whatever mechanism alkyl halides follow for the substitution reactionto occur, the polarity of the carbon hallogen bond is responsible for these substitution reactions. The rates of S_(N)1 reactions are governed by the stability of carbocation whereas for S_(N)2 reactions steric factor is the deciding factor. If the starting material is a chiral compound, we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI is also governed by steric factor and stability of carbocation, which indicates that in organic chemistry, these two major factors help us in deciding the kind of product formed. Q. Give one use of CHI_(3).
Answer» SOLUTION :As an ANTISEPTIC.

9.	Read the given passage and answer the questions The substitution reaction of alkyl halide mainly occurs by S_(N)1 or S_(N)2 mechanism. Whatever mechanism alkyl halides follow for the substitution reactionto occur, the polarity of the carbon hallogen bond is responsible for these substitution reactions. The rates of S_(N)1 reactions are governed by the stability of carbocation whereas for S_(N)2 reactions steric factor is the deciding factor. If the starting material is a chiral compound, we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI is also governed by steric factor and stability of carbocation, which indicates that in organic chemistry, these two major factors help us in deciding the kind of product formed. Q. Predict the stereochemistry of the product formed if an optically active alkyl halide undergoes substitution by S_(N)2 mechanism.
Answer» SOLUTION :The PRODUCT OBTAINED will have INVERTED STRUCTURE.

10.	Read the given passage and answer the questions The substitution reaction of alkyl halide mainly occurs by S_(N)1 or S_(N)2 mechanism. Whatever mechanism alkyl halides follow for the substitution reactionto occur, the polarity of the carbon hallogen bond is responsible for these substitution reactions. The rates of S_(N)1 reactions are governed by the stability of carbocation whereas for S_(N)2 reactions steric factor is the deciding factor. If the starting material is a chiral compound, we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI is also governed by steric factor and stability of carbocation, which indicates that in organic chemistry, these two major factors help us in deciding the kind of product formed. Q. Predict the major product formed when 2-Bromobutane undergoes a reaction with alcoholic KOH.
Answer» SOLUTION :`UNDERSET("But-2-ene")(CH_(3)-CH=CH-CH_(3))`

11.	Read the given passage and answer the questions The substitution reaction of alkyl halide mainly occurs by S_(N)1 or S_(N)2 mechanism. Whatever mechanism alkyl halides follow for the substitution reactionto occur, the polarity of the carbon hallogen bond is responsible for these substitution reactions. The rates of S_(N)1 reactions are governed by the stability of carbocation whereas for S_(N)2 reactions steric factor is the deciding factor. If the starting material is a chiral compound, we may end up with an inverted product or racemic mixture depending upon the type of mechanism followed by alkyl halide. Cleavage of ethers with HI is also governed by steric factor and stability of carbocation, which indicates that in organic chemistry, these two major factors help us in deciding the kind of product formed. Q. Write the structures of the products formed when anisole is treated with HI.
Answer» Solution :`C_(6)H_(5)OH+CH_(3)I`.

12.	Read the given passage and answer the questions:The direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is, now the pure solvent flows out of the solution through the semi permeable membrane. This phenomenon is called reverse osmosis and is of great practical utility. Reverse osmosis is used in the desalination of sea water. When pressure more than the osmotic pressure is applied, pure water is squeezed out of sea water through the membrane. A variety of polymer membranes are available for this purpose.Give one example of a material used in the preparation of membrane.
Answer» SOLUTION :CELLULOSE ACETATE.

13.	Read the given passage and answer the questions:The direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is, now the pure solvent flows out of the solution through the semi permeable membrane. This phenomenon is called reverse osmosis and is of great practical utility. Reverse osmosis is used in the desalination of sea water. When pressure more than the osmotic pressure is applied, pure water is squeezed out of sea water through the membrane. A variety of polymer membranes are available for this purpose.Give one more example of osmosis in daily use.
Answer» SOLUTION :Food GRAINS ALLOW ABSORPTION of water in RAINY season and gain weight.

14.	Read the given passage and answer the questions:The direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is, now the pure solvent flows out of the solution through the semi permeable membrane. This phenomenon is called reverse osmosis and is of great practical utility. Reverse osmosis is used in the desalination of sea water. When pressure more than the osmotic pressure is applied, pure water is squeezed out of sea water through the membrane. A variety of polymer membranes are available for this purpose.What is the function of membrane in reverse osmosis ?
Answer» Solution :Membrane ALLOWS the flow of only solvent and not SOLUTE through it.

15.	Read the given passage and answer the questions that follow : The anomalous behaviour of oxygen, like other members of p-block present in second period is due to its small size and high electronegativity. One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H_2O which is not found in H_2S. The absence of d-orbitals in oxygen limits its covalency to four and in practice, rarely exceeds two. On the other hand, in case of other elements of the group, the valence shells can be expanded and covalence exceeds four. How can we expand the valency shell in the case of elements lying lower in the group of oxygen ?
Answer» Solution :ELEMENTS lying lower in the group of oxygen contain d-orbitals. THEREFORE we can expand the VALENCE SHELL.

16.	Read the given passage and answer the questions that follow : The anomalous behaviour of oxygen, like other members of p-block present in second period is due to its small size and high electronegativity. One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H_2O which is not found in H_2S. The absence of d-orbitals in oxygen limits its covalency to four and in practice, rarely exceeds two. On the other hand, in case of other elements of the group, the valence shells can be expanded and covalence exceeds four. Name the fifth member of the group of oxygen.
Answer» SOLUTION :Polonium is the FIFTH ELEMENT of the oxygen FAMILY.

17.	Read the given passage and answer the questions:The direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is, now the pure solvent flows out of the solution through the semi permeable membrane. This phenomenon is called reverse osmosis and is of great practical utility. Reverse osmosis is used in the desalination of sea water. When pressure more than the osmotic pressure is applied, pure water is squeezed out of sea water through the membrane. A variety of polymer membranes are available for this purpose.Give one utility of reverse osmosis.
Answer» SOLUTION :It can be used to desaline sea WATER to MAKE it SUITABLE for drinking.

18.	Read the given passage and answer the questions:The direction of osmosis can be reversed if a pressure larger than the osmotic pressure is applied to the solution side. That is, now the pure solvent flows out of the solution through the semi permeable membrane. This phenomenon is called reverse osmosis and is of great practical utility. Reverse osmosis is used in the desalination of sea water. When pressure more than the osmotic pressure is applied, pure water is squeezed out of sea water through the membrane. A variety of polymer membranes are available for this purpose.What is meant by reverse osmosis ?
Answer» SOLUTION : Normally, the solvent flows through the membrane from a solution of low CONCENTRATION toa solution of high concentration. If it can flow in the reverse DIRECTION, it is called reverseosmosis.

19.	Read the given passage and answer the questions that follow : The anomalous behaviour of oxygen, like other members of p-block present in second period is due to its small size and high electronegativity. One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H_2O which is not found in H_2S. The absence of d-orbitals in oxygen limits its covalency to four and in practice, rarely exceeds two. On the other hand, in case of other elements of the group, the valence shells can be expanded and covalence exceeds four. H_2O is a water at room temperature whereas H_2S is a gas.
Answer» Solution :Due to high ELECTRONEGATIVITY of OXYGEN, water shows hydrogen BONDING and therefore has a higher boiling point. Therefore it is a liquid at room temperature.

20.	Read the given passage and answer the questionsthat follow : Surface chemistry deals with the phenomena that occur at the surfaces or interfaces. The interface or surface is represented by separating the bulk phases by a hyphen or a slash. For example, the interface between a solid and a gas may be represented by solid-gas or solid/gas. Due to complete miscibility, there is no interface between the gases. The bulk phases that we come across in surface chemistry may be pure compounds or solutions. The interface is normally a few molecules thick but its area depends on the size of the particles of bulk phases. Many important phenomena, noticeable among these being corrosion, electrode processes, heterogeneous catalysis, dissolution and crystallisation occur at interfaces. The subject of surface chemistry finds many applications in industry, analytical work and daily life situations. Which phenomena are studied under surface chemistry ?
Answer» SOLUTION :Corrosion, ELECTRODE process, HETEROGENEOUS catalysis, DISSOLUTION and crystallisation are STUDIED under surface chemistry.

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21.	Read the given passage and answer the questions that follow : The anomalous behaviour of oxygen, like other members of p-block present in second period is due to its small size and high electronegativity. One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H_2O which is not found in H_2S. The absence of d-orbitals in oxygen limits its covalency to four and in practice, rarely exceeds two. On the other hand, in case of other elements of the group, the valence shells can be expanded and covalence exceeds four.First element of the groups in p-block shows anomalous behaviour from other elements of the group. Explain.
Answer» Solution :FIRST member of a group of p-block elements POSSESSES SMALL size and HIGH electronegativity. Therefore they show anomalous BEHAVIOUR.

22.	Read the given passage and answer the questionsthat follow : Surface chemistry deals with the phenomena that occur at the surfaces or interfaces. The interface or surface is represented by separating the bulk phases by a hyphen or a slash. For example, the interface between a solid and a gas may be represented by solid-gas or solid/gas. Due to complete miscibility, there is no interface between the gases. The bulk phases that we come across in surface chemistry may be pure compounds or solutions. The interface is normally a few molecules thick but its area depends on the size of the particles of bulk phases. Many important phenomena, noticeable among these being corrosion, electrode processes, heterogeneous catalysis, dissolution and crystallisation occur at interfaces. The subject of surface chemistry finds many applications in industry, analytical work and daily life situations. Which out of adsorption, catalysis and colloids is studied under surface chemistry ?
Answer» SOLUTION :All the THREE are PART of SURFACE CHEMISTRY.

23.	Read the given passage and answer the questions that follow : The anomalous behaviour of oxygen, like other members of p-block present in second period is due to its small size and high electronegativity. One typical example of effects of small size and high electronegativity is the presence of strong hydrogen bonding in H_2O which is not found in H_2S. The absence of d-orbitals in oxygen limits its covalency to four and in practice, rarely exceeds two. On the other hand, in case of other elements of the group, the valence shells can be expanded and covalence exceeds four. Give the names of third and fourth members of the group to which O and S belong.
Answer» Solution :THIRD member is selenium (Se) and FOURTH member is TELLURIUM (TE).

24.	Read the given passage and answer the questionsthat follow : Surface chemistry deals with the phenomena that occur at the surfaces or interfaces. The interface or surface is represented by separating the bulk phases by a hyphen or a slash. For example, the interface between a solid and a gas may be represented by solid-gas or solid/gas. Due to complete miscibility, there is no interface between the gases. The bulk phases that we come across in surface chemistry may be pure compounds or solutions. The interface is normally a few molecules thick but its area depends on the size of the particles of bulk phases. Many important phenomena, noticeable among these being corrosion, electrode processes, heterogeneous catalysis, dissolution and crystallisation occur at interfaces. The subject of surface chemistry finds many applications in industry, analytical work and daily life situations. How do you define surface chemistry?
Answer» SOLUTION :SURFACE CHEMISTRY deals with the PHENOMENA that occur at the surfaces or interfaces.

25.	Read the given passage and answer the questionsthat follow : Surface chemistry deals with the phenomena that occur at the surfaces or interfaces. The interface or surface is represented by separating the bulk phases by a hyphen or a slash. For example, the interface between a solid and a gas may be represented by solid-gas or solid/gas. Due to complete miscibility, there is no interface between the gases. The bulk phases that we come across in surface chemistry may be pure compounds or solutions. The interface is normally a few molecules thick but its area depends on the size of the particles of bulk phases. Many important phenomena, noticeable among these being corrosion, electrode processes, heterogeneous catalysis, dissolution and crystallisation occur at interfaces. The subject of surface chemistry finds many applications in industry, analytical work and daily life situations. What are the dimensions of the interface and its surface area ?
Answer» SOLUTION :The INTERFACE is NORMALLY a few MM thick and its area depends upon the size of the particles of bulk PHASES.

26.	Read the given passage and answer the questionsthat follow : Surface chemistry deals with the phenomena that occur at the surfaces or interfaces. The interface or surface is represented by separating the bulk phases by a hyphen or a slash. For example, the interface between a solid and a gas may be represented by solid-gas or solid/gas. Due to complete miscibility, there is no interface between the gases. The bulk phases that we come across in surface chemistry may be pure compounds or solutions. The interface is normally a few molecules thick but its area depends on the size of the particles of bulk phases. Many important phenomena, noticeable among these being corrosion, electrode processes, heterogeneous catalysis, dissolution and crystallisation occur at interfaces. The subject of surface chemistry finds many applications in industry, analytical work and daily life situations. Can oxygen/hydrogen form interface ?
Answer» SOLUTION :There will be no INTERFACE between oxygen and hydrogen because the GASES are completely MISCIBLE.

27.	Read the given passage and answer the questions that follow : Potassium chlorate, when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of 653-873 K. 2KClO_3 overset("Heat")to 2KCl + 3O_2 However, when a little of manganese dioxide is added, the decomposition takes place at a considerably lower temperature range, i.e., 473-633 K and also at a much accelerated rate. The added manganese dioxide remains unchanged with respect to its mass and composition. In a similar manner, the rates of a number of a chemical reactions can be altered by the mere presence of a foreign substance. The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius, in 1835. He suggested the term catalyst for such substances. Give another example of a reaction and the catalyst used in the reaction.
Answer» SOLUTION :`N_2(g) + 3H_2(g) UNDERSET(Mo(s))s OVERSET(FE(s))to 2NH_3(g)`

28.	Read the given passage and answer the questions that follow : Potassium chlorate, when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of 653-873 K. 2KClO_3 overset("Heat")to 2KCl + 3O_2 However, when a little of manganese dioxide is added, the decomposition takes place at a considerably lower temperature range, i.e., 473-633 K and also at a much accelerated rate. The added manganese dioxide remains unchanged with respect to its mass and composition. In a similar manner, the rates of a number of a chemical reactions can be altered by the mere presence of a foreign substance. The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius, in 1835. He suggested the term catalyst for such substances. How the catalyst is able to lower down the temperature of reaction ?
Answer» Solution :ACTIVATION ENERGY is lowered in the PRESENCE of CATALYST.

29.	Read the given passage and answer the questions that follow : Potassium chlorate, when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of 653-873 K. 2KClO_3 overset("Heat")to 2KCl + 3O_2 However, when a little of manganese dioxide is added, the decomposition takes place at a considerably lower temperature range, i.e., 473-633 K and also at a much accelerated rate. The added manganese dioxide remains unchanged with respect to its mass and composition. In a similar manner, the rates of a number of a chemical reactions can be altered by the mere presence of a foreign substance. The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius, in 1835. He suggested the term catalyst for such substances. What happens to the catalyst after reactions ?
Answer» Solution :The catalyst REMAINS unchanged with RESPECT to mass and COMPOSITION

30.	Read the given passage and answer the questions that follow : Potassium chlorate, when heated strongly decomposes slowly giving dioxygen. The decomposition occurs in the temperature range of 653-873 K. 2KClO_3 overset("Heat")to 2KCl + 3O_2 However, when a little of manganese dioxide is added, the decomposition takes place at a considerably lower temperature range, i.e., 473-633 K and also at a much accelerated rate. The added manganese dioxide remains unchanged with respect to its mass and composition. In a similar manner, the rates of a number of a chemical reactions can be altered by the mere presence of a foreign substance. The systematic study of the effect of various foreign substances on the rates of chemical reactions was first made by Berzelius, in 1835. He suggested the term catalyst for such substances. Who made a systematic study of the effect of foreign substances on the rates of chemical reactions and when ?
Answer» SOLUTION :BERZELIUS MADE such a STUDY in the YEAR 1835.