15280 + Interview Questions in Chemistry

1.	___% nitric acid is obtained by distilling 68% nitric acid with Conc.H2SO4.
Answer» ___% nitric acid is obtained by distilling 68% nitric acid with Conc. $H_{2} S O_{4}$ .

Discussion

2.	What is the common oxidation state of all the elements of alkali metals, halogens and noble gases?
Answer» What is the common oxidation state of all the elements of alkali metals, halogens and noble gases?

Discussion

3.	The atomic masses of three elements X, Y and Z having similar chemical properties are 7, 23 and 39 respectively. (a) Calculate the average atomic mass of elements X and Z. (b) How does the average atomic mass of elements X and Z compare with the atomic mass of element Y? (c) Which law of classification of elements is illustrated by this example? (d) What could the elements X, Y and Z be? (e) Give another example of a set of elements which can be classified according to this law.
Answer» The atomic masses of three elements X, Y and Z having similar chemical properties are 7, 23 and 39 respectively. (a) Calculate the average atomic mass of elements X and Z. (b) How does the average atomic mass of elements X and Z compare with the atomic mass of element Y? (c) Which law of classification of elements is illustrated by this example? (d) What could the elements X, Y and Z be? (e) Give another example of a set of elements which can be classified according to this law.

3.

The atomic masses of three elements X, Y and Z having similar chemical properties are 7, 23 and 39 respectively. (a) Calculate the average atomic mass of elements X and Z. (b) How does the average atomic mass of elements X and Z compare with the atomic mass of element Y? (c) Which law of classification of elements is illustrated by this example? (d) What could the elements X, Y and Z be? (e) Give another example of a set of elements which can be classified according to this law.

Answer»

The atomic masses of three elements X, Y and Z having similar chemical properties are 7, 23 and 39 respectively.

(a) Calculate the average atomic mass of elements X and Z.

(b) How does the average atomic mass of elements X and Z compare with the atomic mass of element Y?

(c) Which law of classification of elements is illustrated by this example?

(d) What could the elements X, Y and Z be?

(e) Give another example of a set of elements which can be classified according to this law.

Discussion

4.	We say that cooking is also a chemical reaction.so when we cook something we provide heat.and when food is ready it produces heat. Which type of reaction is this Chemical or physical?????
Answer» We say that cooking is also a chemical reaction.so when we cook something we provide heat.and when food is ready it produces heat. Which type of reaction is this Chemical or physical?????

4.

We say that cooking is also a chemical reaction.so when we cook something we provide heat.and when food is ready it produces heat. Which type of reaction is this Chemical or physical?????

Answer»

We say that cooking is also a chemical reaction.so when we cook something we provide heat.and when food is ready it produces heat.

Which type of reaction is this

Chemical or physical?????

Discussion

5.	Which gas is released when a base reacts with a metal carbonate?
Answer» Which gas is released when a base reacts with a metal carbonate?

Discussion

6.	A compound contains 3.2%of oxygen. The minimum moleculer mass weight of the compound is.
Answer» A compound contains 3.2%of oxygen. The minimum moleculer mass weight of the compound is.

Discussion

7.	The pH of a sample of hydrochloric acid is 2. The pH of this sample when diluted by adding some water will be :(1) more than 7(2) more than 2 but less than 7(3) unchanged (4) less than 2 but more than 0
Answer» The pH of a sample of hydrochloric acid is 2. The pH of this sample when diluted by adding some water will be : (1) more than 7 (2) more than 2 but less than 7 (3) unchanged (4) less than 2 but more than 0

Discussion

8.	When quick lime reacts with water it starts boiling why?
Answer» When quick lime reacts with water it starts boiling why?

Discussion

9.	How is electrolytic dissociation different from thermal dissociation?
Answer» How is electrolytic dissociation different from thermal dissociation?

Discussion

10.	How many open chain dienes are possible (without counting stereoisomers) for the formula C5H8?
Answer» How many open chain dienes are possible (without counting stereoisomers) for the formula $C_{5} H_{8}$ ?

Discussion

11.	Question 37Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid, whereas copper does not. Explain why?
Answer» Question 37 Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid, whereas copper does not. Explain why?

Discussion

12.	An element X reacts fairly vigorously with cold water to form Y but hydrogen does not ignite
Answer» An element X reacts fairly vigorously with cold water to form Y but hydrogen does not ignite

Discussion

13.	Due to screening effect of electrons in an atom
Answer» Due to screening effect of electrons in an atom

Discussion

14.	With reference to the electrolysis of acidulated water, answer the following:(a) Why distill water is a non-electrolyte?(b) What is the electrolytic cell called?(c) State what you would observe at the (i) cathode (ii) anode.(d) Summarize the electrode reactions.(e) Why is the electrolysis of acidulated water considered as an example of catalysis?
Answer» With reference to the electrolysis of acidulated water, answer the following: (a) Why distill water is a non-electrolyte? (b) What is the electrolytic cell called? (c) State what you would observe at the (i) cathode (ii) anode. (d) Summarize the electrode reactions. (e) Why is the electrolysis of acidulated water considered as an example of catalysis?

Discussion

15.	What particles are present in pure lead bromide?
Answer» What particles are present in pure lead bromide?

Discussion

16.	Identify the type of chemical reaction taking place when silver chloride turns black on exposure to sunlight.
Answer» Identify the type of chemical reaction taking place when silver chloride turns black on exposure to sunlight.

Discussion

17.	Electricity generated from fossil fuels such as coal and crude oil to run the industries leads to high concentrations of harmful gases in the atmosphere causing ozone depletion and global warming. What do coal and oil have in it that releases as oxides into the atmosphere?
Answer» Electricity generated from fossil fuels such as coal and crude oil to run the industries leads to high concentrations of harmful gases in the atmosphere causing ozone depletion and global warming. What do coal and oil have in it that releases as oxides into the atmosphere?

Discussion

18.	Give the names and structural formula of the first three members of homologous series of alkanes. [3 MARKS]
Answer» Give the names and structural formula of the first three members of homologous series of alkanes. [3 MARKS]

Discussion

19.	WHICH IS A HIGHLY REACTIVE METAL
Answer» WHICH IS A HIGHLY REACTIVE METAL

Discussion

20.	Which of the given mixture will act as buffer?(1) 100 ml, 1 M HCI + 100 ml, 0.5 M NaCI(2) 500 ml, 1 M HCI + 200 ml, 0.2 M NH,OH(3) 10 ml, 0.1 M H3PO4 +5 ml, 0.1 M KOH(4) 200 ml, 1 M H2SO4+ 200 ml, 1 M NaOH
Answer» Which of the given mixture will act as buffer?(1) 100 ml, 1 M HCI + 100 ml, 0.5 M NaCI(2) 500 ml, 1 M HCI + 200 ml, 0.2 M NH,OH(3) 10 ml, 0.1 M H3PO4 +5 ml, 0.1 M KOH(4) 200 ml, 1 M H2SO4+ 200 ml, 1 M NaOH

Discussion

21.	which of the compound will not show geometrical isomerism ?}(1) 2-butene (2) propene (3) 1-phenylpropene(4)2-bromo-buten
Answer» which of the compound will not show geometrical isomerism ?}(1) 2-butene (2) propene (3) 1-phenylpropene(4)2-bromo-buten

Discussion

22.	if electronegativity difference between two atoms is 2 .Then calculate percentage of ionic character in the molecule a.72% b.23% c.46% d.54
Answer» if electronegativity difference between two atoms is 2 .Then calculate percentage of ionic character in the molecule a.72% b.23% c.46% d.54

Discussion

23.	In a reversible reaction, the role played by a catalyst is to
Answer» In a reversible reaction, the role played by a catalyst is to

Discussion

24.	When benzaldehyde is oxidised to give ben acid then the oxidation state of carbon of aldelhyd zoic group is changed from (1) +2 to +3 (2) +1 to +3 (3) Zero to +2 (4) No change
Answer» When benzaldehyde is oxidised to give ben acid then the oxidation state of carbon of aldelhyd zoic group is changed from (1) +2 to +3 (2) +1 to +3 (3) Zero to +2 (4) No change

Discussion

25.	Arrange the following in increasing order of property indicated:(i) Li, Be and B (ionization energy)(ii) F, Cl, Br, I (electron affinity)(iii) SiO2, P2O5, SO3, Cl2O7 (acidic nature)(iv) I, I+, I− (atomic size)
Answer» Arrange the following in increasing order of property indicated: (i) Li, Be and B (ionization energy) (ii) F, Cl, Br, I (electron affinity) (iii) SiO₂, P₂O₅, SO₃, Cl₂O₇ (acidic nature) (iv) I, I⁺, I⁻ (atomic size)

Discussion

26.	0.9 gram aluminium react with dilute HCl to give H2 the volume of hydrogen evolved at STP is
Answer» 0.9 gram aluminium react with dilute HCl to give H2 the volume of hydrogen evolved at STP is

Discussion

27.	The following is an extract from 'Metals in the Service of Man, Alexander and Street/Pelican 1976':'Alumina (Aluminium oxide) has a very high melting point of over 2000 C so that it cannot readily be liquefied. However, conversion of alumina to aluminium and oxygen, by electrolysis, can occur when it is dissolved in some other substance'.(a) Which solution is used to react with bauxite as a first step in obtaining pure aluminium oxide?(b) The aluminium oxide for the electrolytic extraction of aluminium is obtained by heating aluminium hydroxide. Write the balanced chemical equation for this reaction.(c) Name the element which serves both as anode and the cathode in the extraction of aluminium.(d) Write the balanced chemical equation for the reaction that occurs at the cathode during the extraction of aluminium by electrolysis.(e) Give the balanced chemical equation for the reaction which occurs at the anode when aluminium is purified by electrolysis.
Answer» The following is an extract from 'Metals in the Service of Man, Alexander and Street/Pelican 1976': 'Alumina (Aluminium oxide) has a very high melting point of over 2000 C so that it cannot readily be liquefied. However, conversion of alumina to aluminium and oxygen, by electrolysis, can occur when it is dissolved in some other substance'. (a) Which solution is used to react with bauxite as a first step in obtaining pure aluminium oxide? (b) The aluminium oxide for the electrolytic extraction of aluminium is obtained by heating aluminium hydroxide. Write the balanced chemical equation for this reaction. (c) Name the element which serves both as anode and the cathode in the extraction of aluminium. (d) Write the balanced chemical equation for the reaction that occurs at the cathode during the extraction of aluminium by electrolysis. (e) Give the balanced chemical equation for the reaction which occurs at the anode when aluminium is purified by electrolysis.

Discussion

28.	The order of decreasing reactivity towards an electrophilic reagent for the following would be a)benzene b)toluene c)chlorobenzene d)phenol
Answer» The order of decreasing reactivity towards an electrophilic reagent for the following would be a)benzene b)toluene c)chlorobenzene d)phenol

Discussion

29.	Question 20 Observe the circuit given in the figure. Boojho set up this circuit for purification of copper. What will be the nature of – (i) plate A (ii) plate B (iii) the solution. Explain the process of purification.
Answer» Question 20 Observe the circuit given in the figure. Boojho set up this circuit for purification of copper. What will be the nature of – (i) plate A (ii) plate B (iii) the solution. Explain the process of purification.

Discussion

30.	Explain the following reaction with one example each : (i) Substitution reactions (ii) Addition reactions (iii) Combustion reactions (iv) Oxidation reactions
Answer» Explain the following reaction with one example each : (i) Substitution reactions (ii) Addition reactions (iii) Combustion reactions (iv) Oxidation reactions

Discussion

31.	When NaHCO3 is heated , + CO2+H2O is obtained.
Answer» When ${NaHCO}_{3}$ is heated , + ${CO}_{2} + H_{2} O$ is obtained.

Discussion

32.	N2 and H2 are taken in 1:3 molar ratio in a closed vessel to attain the following equilibrium . N2 + 3H2 ----> 2NH3 Find Kp for the reaction at total pressure of 2P if PN2 at equilibrium is P/3 .
Answer» N2 and H2 are taken in 1:3 molar ratio in a closed vessel to attain the following equilibrium . N2 + 3H2 ----> 2NH3 Find Kp for the reaction at total pressure of 2P if PN2 at equilibrium is P/3 .

Discussion

33.	The reaction of potassium permanganate (VII) with acidified iron(II) sulphate is given below: If 15.8 g of potassium permanganate(VII) was used in the reaction, calculate the mass of iron (II) sulphate used in the above reaction. (K = 39, Mn = 55, Fe = 56, S = 32, O = 16)
Answer» The reaction of potassium permanganate (VII) with acidified iron(II) sulphate is given below: If 15.8 g of potassium permanganate(VII) was used in the reaction, calculate the mass of iron (II) sulphate used in the above reaction. (K = 39, Mn = 55, Fe = 56, S = 32, O = 16)

33.

The reaction of potassium permanganate (VII) with acidified iron(II) sulphate is given below: If 15.8 g of potassium permanganate(VII) was used in the reaction, calculate the mass of iron (II) sulphate used in the above reaction. (K = 39, Mn = 55, Fe = 56, S = 32, O = 16)

Answer»

The reaction of potassium permanganate (VII) with acidified iron(II) sulphate is given below:

If 15.8 g of potassium permanganate(VII) was used in the reaction, calculate the mass of iron (II) sulphate used in the above reaction. (K = 39, Mn = 55, Fe = 56, S = 32, O = 16)

Discussion

34.	A mixture of N2 and O2 has a density of 1g/L and the average molecular weight is y g/mol at 27 celsius and 600 mm Hg pressure. the mole fraction of nitrogen is?
Answer» A mixture of N2 and O2 has a density of 1g/L and the average molecular weight is y g/mol at 27 celsius and 600 mm Hg pressure. the mole fraction of nitrogen is?

Discussion

35.	A student took some lead nitrate compound in a boiling tube and heated it strongly. The gas/gases evolved on heating this compound is/are :(1) NO2(2) NO2 + CO2(3) NO2 + O2(4) N2 + O2
Answer» A student took some lead nitrate compound in a boiling tube and heated it strongly. The gas/gases evolved on heating this compound is/are : (1) NO₂ (2) NO₂+ CO₂ (3) NO₂ + O₂ (4) N₂+ O₂

Discussion

36.	Select the most basic oxide1. Mn2O72. MnO23. MnO4. Mn2O3
Answer» Select the most basic oxide 1. Mn2O7 2. MnO2 3. MnO 4. Mn2O3

Discussion

37.	A metal X is in the first group of the periodic table. What will be the formula of its oxide?
Answer» A metal X is in the first group of the periodic table. What will be the formula of its oxide?

Discussion

38.	Give the method of preparation of ethyne from 1, 2-dibromoethane.
Answer» Give the method of preparation of ethyne from 1, 2-dibromoethane.

Discussion

39.	Assertion: Energy of electron is taken negative. Reason: Energy of electron at infinity is zero.
Answer» Assertion: Energy of electron is taken negative. Reason: Energy of electron at infinity is zero.

Discussion

40.	The following statement is correct only under certain conditions. Rewrite the statement including the appropriate conditions.Oxalic acid reacts with sulphuric acid to produce carbon monoxide and carbon dioxide.
Answer» The following statement is correct only under certain conditions. Rewrite the statement including the appropriate conditions. Oxalic acid reacts with sulphuric acid to produce carbon monoxide and carbon dioxide.

Discussion

41.	Draw the orbit structure for each of the following:(a) N2(b) Cl2(c) H2
Answer» Draw the orbit structure for each of the following: (a) N₂ (b) Cl₂ (c) H₂

Discussion

42.	9.What is the chemical formula of SMOGE and SMOKE ?? What is the difference b/w these two,according to chemistry?
Answer» 9.What is the chemical formula of SMOGE and SMOKE ?? What is the difference b/w these two,according to chemistry?

Discussion

43.	In a crystal, cations and anions are held together by
Answer» In a crystal, cations and anions are held together by

43.

In a crystal, cations and anions are held together by

Answer»

In a crystal, cations and anions are held together by

Discussion

44.	Characteristics of p block elements
Answer» Characteristics of p block elements

Discussion

45.	Explain by writing a word equation.a. Respiration is a chemical change.b. Hard water gets softened on mixing with a solutions of washing soda.c. Lime stone powder disappears on adding to dilute hydrochloric acids.d. Bubbles are seen on adding lemon juice to baking soda.
Answer» Explain by writing a word equation. a. Respiration is a chemical change. b. Hard water gets softened on mixing with a solutions of washing soda. c. Lime stone powder disappears on adding to dilute hydrochloric acids. d. Bubbles are seen on adding lemon juice to baking soda.

Discussion

46.	a metal M of equivalent mass E forms an oxide of molecular formula M_xO_{y }. the atomic mass of the metal is given by the metal is given by the correct equation (a).2E(y/x) (b).xyE (c).E/y (d).y/E (e).E/2(x/y
Answer» a metal M of equivalent mass E forms an oxide of molecular formula M_xO_{y }. the atomic mass of the metal is given by the metal is given by the correct equation (a).2E(y/x) (b).xyE (c).E/y (d).y/E (e).E/2(x/y

Discussion

47.	An element reacts with oxygen to give a compound with a high melting point.The element is likely to be (A) Calcium (B) Silicon (C) Carbon (D) Iron
Answer» An element reacts with oxygen to give a compound with a high melting point.The element is likely to be (A) Calcium (B) Silicon (C) Carbon (D) Iron

47.

An element reacts with oxygen to give a compound with a high melting point.The element is likely to be (A) Calcium (B) Silicon (C) Carbon (D) Iron

Answer»

An element reacts with oxygen to give a compound with a high melting point.The element is likely to be

(A) Calcium

(B) Silicon

(C) Carbon

(D) Iron

Discussion

48.	The number of atoms of Na in 8 g of its sample is x×1023.The value of x( rounded off to the nearest integer) is [Given : NA=6.02×1023mol−1 and Atomic mass of Na=23.0u]
Answer» The number of atoms of Na in 8 g of its sample is $x \times 10^{23}$ .The value of x( rounded off to the nearest integer) is [Given : $N_{A} = 6.02 \times 10^{23} m o l^{- 1}$ and Atomic mass of Na=23.0u]

Discussion

49.	18.First and second ionization energies of magnesium are 7.646 and 15.035 electron volt respectively. The amount of energy in kilo Joule needed to convert all the atoms of magnesium into Mg2+ ions present in 12 mg of magnesium vapours .
Answer» 18.First and second ionization energies of magnesium are 7.646 and 15.035 electron volt respectively. The amount of energy in kilo Joule needed to convert all the atoms of magnesium into Mg2+ ions present in 12 mg of magnesium vapours .

Discussion

50.	Which amongst the following is the electron dot structure of H2 molecule?
Answer» Which amongst the following is the electron dot structure of $H_{2}$ molecule?

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

___% nitric acid is obtained by distilling 68% nitric acid with Conc.H2SO4.

What is the common oxidation state of all the elements of alkali metals, halogens and noble gases?

We say that cooking is also a chemical reaction.so when we cook something we provide heat.and when food is ready it produces heat. Which type of reaction is this Chemical or physical?????

Which gas is released when a base reacts with a metal carbonate?

A compound contains 3.2%of oxygen. The minimum moleculer mass weight of the compound is.

The pH of a sample of hydrochloric acid is 2. The pH of this sample when diluted by adding some water will be :(1) more than 7(2) more than 2 but less than 7(3) unchanged (4) less than 2 but more than 0

When quick lime reacts with water it starts boiling why?

How is electrolytic dissociation different from thermal dissociation?

How many open chain dienes are possible (without counting stereoisomers) for the formula C5H8?

Question 37Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid, whereas copper does not. Explain why?

An element X reacts fairly vigorously with cold water to form Y but hydrogen does not ignite

Due to screening effect of electrons in an atom

What particles are present in pure lead bromide?

Identify the type of chemical reaction taking place when silver chloride turns black on exposure to sunlight.

Electricity generated from fossil fuels such as coal and crude oil to run the industries leads to high concentrations of harmful gases in the atmosphere causing ozone depletion and global warming. What do coal and oil have in it that releases as oxides into the atmosphere?

Give the names and structural formula of the first three members of homologous series of alkanes. [3 MARKS]

WHICH IS A HIGHLY REACTIVE METAL

Which of the given mixture will act as buffer?(1) 100 ml, 1 M HCI + 100 ml, 0.5 M NaCI(2) 500 ml, 1 M HCI + 200 ml, 0.2 M NH,OH(3) 10 ml, 0.1 M H3PO4 +5 ml, 0.1 M KOH(4) 200 ml, 1 M H2SO4+ 200 ml, 1 M NaOH

which of the compound will not show geometrical isomerism ?}(1) 2-butene (2) propene (3) 1-phenylpropene(4)2-bromo-buten

if electronegativity difference between two atoms is 2 .Then calculate percentage of ionic character in the molecule a.72% b.23% c.46% d.54

In a reversible reaction, the role played by a catalyst is to

When benzaldehyde is oxidised to give ben acid then the oxidation state of carbon of aldelhyd zoic group is changed from (1) +2 to +3 (2) +1 to +3 (3) Zero to +2 (4) No change

Arrange the following in increasing order of property indicated:(i) Li, Be and B (ionization energy)(ii) F, Cl, Br, I (electron affinity)(iii) SiO2, P2O5, SO3, Cl2O7 (acidic nature)(iv) I, I+, I− (atomic size)

0.9 gram aluminium react with dilute HCl to give H2 the volume of hydrogen evolved at STP is

The order of decreasing reactivity towards an electrophilic reagent for the following would be a)benzene b)toluene c)chlorobenzene d)phenol

Question 20 Observe the circuit given in the figure. Boojho set up this circuit for purification of copper. What will be the nature of – (i) plate A (ii) plate B (iii) the solution. Explain the process of purification.

Explain the following reaction with one example each : (i) Substitution reactions (ii) Addition reactions (iii) Combustion reactions (iv) Oxidation reactions

When NaHCO3 is heated , + CO2+H2O is obtained.

N2 and H2 are taken in 1:3 molar ratio in a closed vessel to attain the following equilibrium . N2 + 3H2 ----> 2NH3 Find Kp for the reaction at total pressure of 2P if PN2 at equilibrium is P/3 .

The reaction of potassium permanganate (VII) with acidified iron(II) sulphate is given below: If 15.8 g of potassium permanganate(VII) was used in the reaction, calculate the mass of iron (II) sulphate used in the above reaction. (K = 39, Mn = 55, Fe = 56, S = 32, O = 16)

A mixture of N2 and O2 has a density of 1g/L and the average molecular weight is y g/mol at 27 celsius and 600 mm Hg pressure. the mole fraction of nitrogen is?

A student took some lead nitrate compound in a boiling tube and heated it strongly. The gas/gases evolved on heating this compound is/are :(1) NO2(2) NO2 + CO2(3) NO2 + O2(4) N2 + O2

Select the most basic oxide1. Mn2O72. MnO23. MnO4. Mn2O3

A metal X is in the first group of the periodic table. What will be the formula of its oxide?

Give the method of preparation of ethyne from 1, 2-dibromoethane.

Assertion: Energy of electron is taken negative. Reason: Energy of electron at infinity is zero.

The following statement is correct only under certain conditions. Rewrite the statement including the appropriate conditions.Oxalic acid reacts with sulphuric acid to produce carbon monoxide and carbon dioxide.

Draw the orbit structure for each of the following:(a) N2(b) Cl2(c) H2

9.What is the chemical formula of SMOGE and SMOKE ?? What is the difference b/w these two,according to chemistry?

In a crystal, cations and anions are held together by

Characteristics of p block elements

Explain by writing a word equation.a. Respiration is a chemical change.b. Hard water gets softened on mixing with a solutions of washing soda.c. Lime stone powder disappears on adding to dilute hydrochloric acids.d. Bubbles are seen on adding lemon juice to baking soda.

a metal M of equivalent mass E forms an oxide of molecular formula M_xO_{y }. the atomic mass of the metal is given by the metal is given by the correct equation (a).2E(y/x) (b).xyE (c).E/y (d).y/E (e).E/2(x/y

An element reacts with oxygen to give a compound with a high melting point.The element is likely to be (A) Calcium (B) Silicon (C) Carbon (D) Iron

The number of atoms of Na in 8 g of its sample is x×1023.The value of x( rounded off to the nearest integer) is [Given : NA=6.02×1023mol−1 and Atomic mass of Na=23.0u]

18.First and second ionization energies of magnesium are 7.646 and 15.035 electron volt respectively. The amount of energy in kilo Joule needed to convert all the atoms of magnesium into Mg2+ ions present in 12 mg of magnesium vapours .

Which amongst the following is the electron dot structure of H2 molecule?