94420 + Interview Questions in Chemistry in Class 12

1.	In melting lattice, structure of solid
Answer» Remain unchanged CHANGE BECOMES compact None of the above ANSWER :B

Discussion

2.	In mechanism of aldol condensation reaction the second step is
Answer» abstraction of `alpha `- H ATOM carbon of aldehyde by base to form carbanion The attack of carbanionon CARBONYL carbon atom of another moleculeto form alkoxide ion The attck of carbonion on carbonyl carbon atom of another molecule to form OXOCATION Alkkoxide ion take proton from water to form `beta` - hydroxy aldehyde ANSWER :B

Discussion

3.	In marshy places, the plants decay quite fast. Assign reson.
Answer» SOLUTION :Plant ROOTS burst because of EXTRA intake of WAER.

Discussion

4.	In Mayer's relation: C_(P)-C_(V)=R 'R' stands for:
Answer» translational kinetic ENERGY of 1 mol gas rotational kinetic energy of 1 mol gas vibrational kinetic energy of 1 mol gas work done to increase the TEMPERATURE of 1 mol gas by ONE degree Answer :D

Discussion

5.	In many reactions, the reaction proceeds in a sequence of steps, so the overall rate is determined by:
Answer» OUTER of DIFFERENT steps Slowest step Molecularity of the steps Fastest step Answer :B

Discussion

6.	In macromolecular type of colloids, the dispersed particles are themselves large molecules (usually polymers). Since these molecules have dimensions comparable to those of colloidal particles, their dispersions are called macromolecular colloids. Most lyophilic sols belong to this category. These are certain colloids which behave as normal strong electrolytes at low concentrations, but exhibit colloidal properties at higher concentrations due to the formation of aggregated particles. These are known as micelles or associated colloids. Surface active agents like soaps and synthetic detergents belong to this class. Critical micelle concentration (CMC) is the lowest concentration at which micelle formation appears. CMC increases with the total surfactant concentration. At concentration higher than CMC, they form extended parallel sheets known as lamellar micelles which resemble biological membranes. With two molecules thick, the individual molecule is perpendicular to the sheets such that hydrophilic groups are on the outside in aqueous solution and on the inside is a non-polar medium. In concentrated solution, micelles take the form of long cylinders packed in hexagonal arrays and are called lytotroic measomorphs. In an aqueous solution (polar medium), the polar group points towards the periphery and the hydrophobic hydrocarbon chains point towards the conforming the core of the micelle. Mecelles from the ionic surfactants can be formed only above a certain temperature called the Kraft temperature. They are capable of forming ions Molecules of soaps and detergents consist of lyophilic as well as lyophilic parts which associate together to form micelles. Micelles may contain as many as 100 molecules or more. Cleansing action of soap occurs because :
Answer» OIL and greases can be absorbed into the hyrophobic centres of SOAP micelles and washed away oil and grease can be absorbed into HYDROPHILIC centres of soap micelles ACID washed away oil and grease can be absorbed into both hydrophilic and hydrophobic centres but not washed away cleansing action is not related to micelles Answer :A

Discussion

7.	In many reactions, the reaction proceeds in a sequence of stemps, so the overall rate is determined by
Answer» order of different steps slowest step molecularity of the stemps FASTEST step Solution :Slowest step of REACTIONS decides the RATE expression.

Discussion

8.	In macromolecular type of colloids, the dispersed particles are themselves large molecules (usually polymers). Since these molecules have dimensions comparable to those of colloidal particles, their dispersions are called macromolecular colloids. Most lyophilic sols belong to this category. These are certain colloids which behave as normal strong electrolytes at low concentrations, but exhibit colloidal properties at higher concentrations due to the formation of aggregated particles. These are known as micelles or associated colloids. Surface active agents like soaps and synthetic detergents belong to this class. Critical micelle concentration (CMC) is the lowest concentration at which micelle formation appears. CMC increases with the total surfactant concentration. At concentration higher than CMC, they form extended parallel sheets known as lamellar micelles which resemble biological membranes. With two molecules thick, the individual molecule is perpendicular to the sheets such that hydrophilic groups are on the outside in aqueous solution and on the inside is a non-polar medium. In concentrated solution, micelles take the form of long cylinders packed in hexagonal arrays and are called lytotroic measomorphs. In an aqueous solution (polar medium), the polar group points towards the periphery and the hydrophobic hydrocarbon chains point towards the conforming the core of the micelle. Mecelles from the ionic surfactants can be formed only above a certain temperature called the Kraft temperature. They are capable of forming ions Molecules of soaps and detergents consist of lyophilic as well as lyophilic parts which associate together to form micelles. Micelles may contain as many as 100 molecules or more. In multimolecular colloidal sols, atoms or molecules are held together by :
Answer» H-bonding van DER WAALS forces ionic bonding polar COVALENT bonding Answer :B

Discussion

9.	In macromolecular type of colloids, the dispersed particles are themselves large molecules (usually polymers). Since these molecules have dimensions comparable to those of colloidal particles, their dispersions are called macromolecular colloids. Most lyophilic sols belong to this category. These are certain colloids which behave as normal strong electrolytes at low concentrations, but exhibit colloidal properties at higher concentrations due to the formation of aggregated particles. These are known as micelles or associated colloids. Surface active agents like soaps and synthetic detergents belong to this class. Critical micelle concentration (CMC) is the lowest concentration at which micelle formation appears. CMC increases with the total surfactant concentration. At concentration higher than CMC, they form extended parallel sheets known as lamellar micelles which resemble biological membranes. With two molecules thick, the individual molecule is perpendicular to the sheets such that hydrophilic groups are on the outside in aqueous solution and on the inside is a non-polar medium. In concentrated solution, micelles take the form of long cylinders packed in hexagonal arrays and are called lytotroic measomorphs. In an aqueous solution (polar medium), the polar group points towards the periphery and the hydrophobic hydrocarbon chains point towards the conforming the core of the micelle. Mecelles from the ionic surfactants can be formed only above a certain temperature called the Kraft temperature. They are capable of forming ions Molecules of soaps and detergents consist of lyophilic as well as lyophilic parts which associate together to form micelles. Micelles may contain as many as 100 molecules or more. Which part of the soap (RCOO^(–)) dissolves greases and forms micelle ?
Answer» R PART (called TAIL of the ANION) `-COO^(-)` part (called head of the anion) both (A) and (B) none of these Answer :A

Discussion

10.	In macromolecular type of colloids, the dispersed particles are themselves large molecules (usually polymers). Since these molecules have dimensions comparable to those of colloidal particles, their dispersions are called macromolecular colloids. Most lyophilic sols belong to this category. These are certain colloids which behave as normal strong electrolytes at low concentrations, but exhibit colloidal properties at higher concentrations due to the formation of aggregated particles. These are known as micelles or associated colloids. Surface active agents like soaps and synthetic detergents belong to this class. Critical micelle concentration (CMC) is the lowest concentration at which micelle formation appears. CMC increases with the total surfactant concentration. At concentration higher than CMC, they form extended parallel sheets known as lamellar micelles which resemble biological membranes. With two molecules thick, the individual molecule is perpendicular to the sheets such that hydrophilic groups are on the outside in aqueous solution and on the inside is a non-polar medium. In concentrated solution, micelles take the form of long cylinders packed in hexagonal arrays and are called lytotroic measomorphs. In an aqueous solution (polar medium), the polar group points towards the periphery and the hydrophobic hydrocarbon chains point towards the conforming the core of the micelle. Mecelles from the ionic surfactants can be formed only above a certain temperature called the Kraft temperature. They are capable of forming ions Molecules of soaps and detergents consist of lyophilic as well as lyophilic parts which associate together to form micelles. Micelles may contain as many as 100 molecules or more. Select incorrect statement(s) :
Answer» Surface active agent like soaps and synthetic DETERGENTS can form micelles Soaps may ACT as emulsifying agents `C_(17)H_(35)`(hydrocarbon part) and `–COO^(–)` (carboxylate) part of stearate ion `(C_(17)H_(35)COO^(–))` both are hydrophobic All are INCORRECT statements Answer :C

Discussion

11.	In macromolecular type of colloids, the dispersed particles are themselves large molecules (usually polymers). Since these molecules have dimensions comparable to those of colloidal particles, their dispersions are called macromolecular colloids. Most lyophilic sols belong to this category. These are certain colloids which behave as normal strong electrolytes at low concentrations, but exhibit colloidal properties at higher concentrations due to the formation of aggregated particles. These are known as micelles or associated colloids. Surface active agents like soaps and synthetic detergents belong to this class. Critical micelle concentration (CMC) is the lowest concentration at which micelle formation appears. CMC increases with the total surfactant concentration. At concentration higher than CMC, they form extended parallel sheets known as lamellar micelles which resemble biological membranes. With two molecules thick, the individual molecule is perpendicular to the sheets such that hydrophilic groups are on the outside in aqueous solution and on the inside is a non-polar medium. In concentrated solution, micelles take the form of long cylinders packed in hexagonal arrays and are called lytotroic measomorphs. In an aqueous solution (polar medium), the polar group points towards the periphery and the hydrophobic hydrocarbon chains point towards the conforming the core of the micelle. Mecelles from the ionic surfactants can be formed only above a certain temperature called the Kraft temperature. They are capable of forming ions Molecules of soaps and detergents consist of lyophilic as well as lyophilic parts which associate together to form micelles. Micelles may contain as many as 100 molecules or more. Surfactant molecules can cluster together as micelles, which are colloid sized cluster of molecules. Micelles form only above critical micelle concentration (CMC) and above certain temperature called kraft temperature. Which is false about micelle formation ?
Answer» `DELTAS` of MICELLE formation is positive the hydrophobic PART lie TOWARDS INTERIOR of micelle in water the hydrophilic part lie towards surface or micelle in water `DeltaS` of micelle formation is negative Answer :D

Discussion

12.	In m_(1)g of a metal A displaces m_(2)G of another metal B from its salt solution and if their equivalent masses are E_(1) and E_(2) respectively, then the equivalent mass of A can be expressed as:
Answer» `E_(1)=(m_(2)xxE_(2))/(m_(1))` `E_(1)=(m_(1))/(m_(2))xxE_(2)` `E_(1)=(m_(1)xxm_(2))/(E_(2))` `E_(1)=sqrt((m_(1))/(m_(2))xxE_(2))` Answer :B

Discussion

13.	In Mac-Arthur Forrest Cyanide method, silver is extracted from the solution of Na[Ag(CN)_2] by the use of
Answer» Zn Pt Au Pd Answer :A

Discussion

14.	In "lucas test" which of the following alcohol cannot give any change ?
Answer» Butylalcohol 2-butanol 2-methylpropan-2-ol 2-propanol Solution :Butylalcohol

Discussion

15.	In Lucas test …………….... alcohol do not react at roorm temperature.
Answer» SOLUTION :PRIMARY

Discussion

16.	In Lssaingne's test for nitrogen, the blue colour is due to the formation od:
Answer» FERRIC ferrocyanide Potassium ferrocyanide Sodium ferrocyanide Sodium cyanide Answer :A

Discussion

17.	In lithium tetrahydroaluminate, the ligand is:
Answer» `AI^+` H `H^-` None Answer :C

Discussion

18.	Fill in the blanks : In the compound lithium tetrahydrido aluminate, the ligand is …………
Answer» `AI^+` H `H^-` None Answer :C

Discussion

19.	In living cells which is dangerous, plasmolysis or haemolysis ?
Answer» Solution :Both plasmolysis and haemolysis are DANGEROUS. CONTENTS will COME out of the cell during plasmolysis and cell collapses. Contents will enter into the cell during haemolysis and cell bursts.

Discussion

20.	In limited supply of oxygen C & Si are allowed to teacted at sufficiently high temperatures in separate vesseles, favourable products are:
Answer» `CO_(2)` & `SiO_(2)` `CO,CO_(2) SIO` & `SiO_(2)` `CO,CO_(2)` & `SiO_(2)` `CO` & `SiO_(2)` SOLUTION :N//A

Discussion

21.	In liquidphasenitrationof alkanesmainly formes
Answer» MONONITRO COMPOUNDS dinitro compounds trinitrocompounds polynitrocompounds SOLUTION :Decrete MOLECULES of REACTANTS

Discussion

22.	In Lewis structure of ozone (O_(3)), formal charges on all three oxygen atoms can be?
Answer» 0,0,0 `+1,-1,0` `+1,+1,+1` `+1,0,+1` Solution :`["BASIC nature of oxide"prop"Metallic character"prop(1)/(I.P.)]` `therefore K_(2)O-`Most basic.

Discussion

23.	In Leclanche cell, MnO_(2) acts as a____.
Answer» SOLUTION :DEPOLARIZER

Discussion

24.	In lime kiln,the reversible reaction, CaCO_3(s) hArr CaO(s)+CO_2(g) proceeds to completion because:
Answer» of HIGH TEMPERATURE `CO_2` ESCAPES out Cao is removed of LOW temperature Answer :B

Discussion

25.	In Lessaigne's test for N,S and halogens, the organic compound is:
Answer» FUSED with SODIUM DISSOLVED with sodamide Extracted with sodamide Fused with calcium Answer :A

Discussion

26.	In lead storage battery, the cathode consists of____.
Answer» SOLUTION :LEAD GRIDS FILLED with lead dioxide `(PbO_(2))`

Discussion

27.	In lead storage battery, the anode reaction is
Answer» `Pb^(2+) + 2e^(-) to Pb` `Pb + H_(2)SO_(4) to PbSO_(4) + 2H^(+) + 2e^(-)` `PbO + H_(2)SO_(4) to PbSO_(4) + H_(2)O` NONE ofthese Answer :B

Discussion

28.	In lead accumulator the electrolyte used is
Answer» `10% H_(2)SO_(4)` with specific GRAVITY 2.15 38%` H_(2)SO_(4)` with specific gravity 1.28 10% `H_(2)SO_(4)` with specific gravity 2.215 38% `H_(2)SO_(4)` with specific gravity 2.15 Solution :38% `H_(2)SO_(4)` with 1.2 g/ML DENSITY is USED in lead accumulator. `M=(W)/(m)xx(1000)/(100xxd)=(38)/(98)xx(1000)/(100xx1.2)=3.2 M`

Discussion

29.	In layer test of I^(-)and Br^(-). If reddish -brown layer comes first then -
Answer» `BR^(-)` present `I^(-)` ABSENT Both (1) and (2) None of these Answer :C

Discussion

30.	In Lassaigne's test when bothN and S are present, blood red colour obtained is due to the formation of:
Answer» FERRIC ferrocyanide Ferric thiocyanate Ferric CYANIDE NONE of these Answer :B

Discussion

31.	In Lassaigne's test, the organic compoundis first fused with sodium metal. The sodium is used because.
Answer» The MELTING point of sodium metal is low sodium metal reacts with elementspresent in organic compounds to form INORGANIC compounds. All sodium salts are solubleiin WATER All sodium salts are soluble in water Solution :(a) and (b) and (C ) are TRUE because sodium has weak metallicbond due to larger size, as well as ionisation enery. Sodium salts are soluble in water because hydration energy dominatesover latticenergy. It follows that (d ) is incorrect.

Discussion

32.	In Lassaigne's test the organic compound is fused with Na followed by extraction with distilled water. Which of the following is not possible fusion product?
Answer» NaNC NACN `Na_(2)S` NaCNS Solution :`NA + C + N to NaCN , 2Na+S to Na_(2)S, Na + X to Nax: Na + C + N +S to NaSCN`

Discussion

33.	In Lassaigne's test sodium metal isused because :
Answer» It is very reactive Its MELTING POINT is low Its COMPOUNDS are SOLUBLE in water All of these Answer :D

Discussion

34.	In Lassaigne's test the organic compound is fused with Na followed by extraction with distilled water. Which of the following is not the possible product of this fusion reaction.
Answer» `NaX` `NACN` `NaNC` `Na_(2)S` Solution :N//A

Discussion

35.	In Lassaigne's test for the detection of halogens, the sodium fusion extract is first boiled with concentrated nitric acid. This is
Answer» to remove silver halides to DECOMPOSE `Na_(2)S`and `NaCN`, if present to dissolve `Ag_(2)S` to dissolve `AgCN`, if formed Answer :B

Discussion

36.	In Lassaigne's test, the organic compound is first fused with sodium metal The sodium metal is used because
Answer» The melting point of SODIUM metal is low Sodium metal reacts with ELEMENTS present in organic COMPOUNDS to form inorganic compounds. All sodium salts are SOLUBLE in water All sodium salts are not soluble in water Solution :Sodium metal is used in Lassaigne.s test DUE to melting point of sodium metal is law and sodium metal reacts with elements present in organic compound to form inorganic compound all sodium salts and soluble in water.

Discussion

37.	In Lassaigne's test for N, the blue colour is due to the formation of :
Answer» POTASSIUM FERRICYANIDE SODIUM CYANIDE Sodium FERROCYANIDE Ferri-ferrocyanide. Answer :D

Discussion

38.	In Lassagine's test, when both N and S are present, blood red colour is obtained. This is due to the formation of :
Answer» FERRIC ferrocyanide Ferric cyanide Ferric thiocyanate Ferric hydroxide Answer :C

Discussion

39.	In lanthanoides the increase in at. No. 14 results in decrease of atomic radii by only 10 pm. Because of
Answer» GRADUAL decrease in nuclear CHARGE gradual decrease in nuclear charge 4f-orbirtals provids less SHIELDING effect 4f-orbitals provides more shielding effect ANSWER :C

Discussion

40.	In lanthanides, the differential electron is filled in
Answer» sf-orbital 4d-orbital 6f-orbital 4f-orbital ANSWER :D

Discussion

41.	In lanthanide series, which element is well known to exhibit +4 oridation state ? Why?
Answer» Solution :Cerium is known to exhibit `+4` state. Example of `Ce^(4+)` in compounds is `CeF_(4)` or `Ce(SO_(4))_2). This is because `Ce^(4+)` has INERT gas ELECTRONIC configuration.

Discussion

42.	In lantanide the nuclear charge
Answer» increases FORM Ce to Lu decreasesfrom Ce to Lu REMAIN same increases up to C to GD and then decreases Answer :A

Discussion

43.	In Langmuir's model of adsorption of a gas on solid surface
Answer» the rate of dissociation of adsorbed molecule FORM the surface does not depend on the surface covered the adsorption at a single SITE on the surface may involve multiple MOLECULES at the same time The mass of gas STRIKING a given area of surface is proportional to the pressure of the gas the mass of the gas striking a given area of surface is independent of the pressure of the gas Answer :C

Discussion

44.	In langmuir's model of adsorption of a gas on a solid surface
Answer» <P>the mass of gas striking a given area of surface is proportional to the presence of the gas the gas striking a given area of surface is independent of the pressure of the gas the rate of dissociation of adsorbed molecules from the surface does not depend on the surface corved the adsorption at a single site on the surface may involve MULTIPLE molecules at the same time Solution :Accoding to Langmuir's model of adsorption of gas on a solid surface the mass of gas adsorbed (x) PER gram of the adsorbent (m) is DIRECTLY proportional to the pressure of the gas (p) at constant TEMPERATURE i.e., `(x)/(m)propp`

Discussion

45.	In labosratory, benzene diazonium chloride is not isolated in the crystalline solid state since in solid state it
Answer» is READILY oxidised explodes is readily reduced is polymerised Solution :SEE PROPERTIES of DIAZONIUM SALT.

Discussion

46.	In Langmuir adsorption isotherm, what is the slope and Y-intercept?
Answer» SOLUTION :`(x)/(m)=(aP)/(1+bP)(or)(P)/((x//m))=(1+bP)/(a)(P)/(x//m)=(1)/(a)+((b)/(a))P (or)(P)/(x//m)=((b)/(a))P+(1)/(a)` A plot of `((P)/(x//m))` versus P is a STRAIGHT line with Y-intercept equa to 1/a and SLOPE equal to b/a.

Discussion

47.	In laboratory SO_2 is prepared easily by
Answer» The ACTION of MODERATELY CONCENTRATED `H_2SO_4` on sulphite The action of `H_2SO_4` on SODIUM sulphide The action of `H_2SO_4` on sodium sulphate None of these Solution :`Na_2SO_3 + H_2SO_4 to Na_2SO_4+ H_2O + SO_2`

Discussion

48.	In laboratory hydrochloric acid can be prepared by heating soidum chloride with which acid
Answer» CON.`H_(2)SO_(4)` Dil. `H_(2)SO_(4)` Con. `HNO_(3)` Di. `HNO_(3)` Answer :A

Discussion

49.	In laboratory burners, we use
Answer» Producers gas Oil gas Gobar gas Coal gas Solution :In laboratory burners, oil gas is GENERALLY used. Oil gas is mixture of `CH_(4)+CO+CO_(2)+H_(2)`

Discussion

50.	In laboratory method HCl gas can dried by passing through
Answer» `P_(4)O_(10)` `SO_(2)` Con. `H_(2)SO_(4)` Con. `HNO_(3)` Answer :C

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

In melting lattice, structure of solid

In mechanism of aldol condensation reaction the second step is

In marshy places, the plants decay quite fast. Assign reson.

In Mayer's relation: C_(P)-C_(V)=R 'R' stands for:

In many reactions, the reaction proceeds in a sequence of steps, so the overall rate is determined by:

In many reactions, the reaction proceeds in a sequence of stemps, so the overall rate is determined by

In m_(1)g of a metal A displaces m_(2)G of another metal B from its salt solution and if their equivalent masses are E_(1) and E_(2) respectively, then the equivalent mass of A can be expressed as:

In Mac-Arthur Forrest Cyanide method, silver is extracted from the solution of Na[Ag(CN)_2] by the use of

In "lucas test" which of the following alcohol cannot give any change ?

In Lucas test …………….... alcohol do not react at roorm temperature.

In Lssaingne's test for nitrogen, the blue colour is due to the formation od:

In lithium tetrahydroaluminate, the ligand is:

Fill in the blanks : In the compound lithium tetrahydrido aluminate, the ligand is …………

In living cells which is dangerous, plasmolysis or haemolysis ?

In limited supply of oxygen C & Si are allowed to teacted at sufficiently high temperatures in separate vesseles, favourable products are:

In liquidphasenitrationof alkanesmainly formes

In Lewis structure of ozone (O_(3)), formal charges on all three oxygen atoms can be?

In Leclanche cell, MnO_(2) acts as a____.

In lime kiln,the reversible reaction, CaCO_3(s) hArr CaO(s)+CO_2(g) proceeds to completion because:

In Lessaigne's test for N,S and halogens, the organic compound is:

In lead storage battery, the cathode consists of____.

In lead storage battery, the anode reaction is

In lead accumulator the electrolyte used is

In layer test of I^(-)and Br^(-). If reddish -brown layer comes first then -

In Lassaigne's test when bothN and S are present, blood red colour obtained is due to the formation of:

In Lassaigne's test, the organic compoundis first fused with sodium metal. The sodium is used because.

In Lassaigne's test the organic compound is fused with Na followed by extraction with distilled water. Which of the following is not possible fusion product?

In Lassaigne's test sodium metal isused because :

In Lassaigne's test the organic compound is fused with Na followed by extraction with distilled water. Which of the following is not the possible product of this fusion reaction.

In Lassaigne's test for the detection of halogens, the sodium fusion extract is first boiled with concentrated nitric acid. This is

In Lassaigne's test, the organic compound is first fused with sodium metal The sodium metal is used because

In Lassaigne's test for N, the blue colour is due to the formation of :

In Lassagine's test, when both N and S are present, blood red colour is obtained. This is due to the formation of :

In lanthanoides the increase in at. No. 14 results in decrease of atomic radii by only 10 pm. Because of

In lanthanides, the differential electron is filled in

In lanthanide series, which element is well known to exhibit +4 oridation state ? Why?

In lantanide the nuclear charge

In Langmuir's model of adsorption of a gas on solid surface

In langmuir's model of adsorption of a gas on a solid surface

In labosratory, benzene diazonium chloride is not isolated in the crystalline solid state since in solid state it

In Langmuir adsorption isotherm, what is the slope and Y-intercept?

In laboratory SO_2 is prepared easily by

In laboratory hydrochloric acid can be prepared by heating soidum chloride with which acid

In laboratory burners, we use

In laboratory method HCl gas can dried by passing through