🧪 NCERT Class 11 MCQ Quiz Hub

1. Third law of thermodynamics provides a method to evaluate which property?
Absolute Energy
Absolute Enthalpy
Absolute Entropy
Absolute Free Energy

2. One mole of which of the following has the highest entropy?
Liquid Nitrogen
Hydrogen Gas
Mercury
Diamond

3. The enthalpy of vaporisation of a substance is 8400 J mol-1 and its boiling point is –173°C. The entropy change for vaporisation is :
84 J mol-1K-1
21 J mol-1K-1
49 J mol-1K-1
12 J mol-1K-1

4. The species which by definition has ZERO standard molar enthalpy of formation at 298 K is
Br2(g)
Cl2(g)
H2O(g)
CH4(g)

5. In a reversible process the system absorbs 600 kJ heat and performs 250 kJ work on the surroundings. What is the increase in the internal energy of the system?
850 kJ
600 kJ
350 kJ
250 kJ

6. Which of the following is true for the reaction? H2O (l) ↔ H2O (g) at 100° C and 1 atm pressure
∆S = 0
∆H = T ∆S
∆H = ∆U
∆H = 0

7. Calculate the heat required to make 6.4 Kg CaC2 from CaO(s) and C(s) from the reaction: CaO(s) + 3 C(s) → CaC2(s) + CO (g) given that ∆f Ho (CaC2) = -14.2 kcal. ∆f H° (CO) = -26.4 kcal.
5624 kcal
1.11 × 104 kcal
86.24 × 10³
1100 kcal

8. In a system where ∆E = -51.0 kJ, a piston expanded against a pext of 1.2 atm giving a change in volume of 32.0 L. What was the change in heat of this system?
-36 kJ
-13 kJ
-47 kJ
24 kJ

9. A system absorb 10 kJ of heat at constant volume and its temperature rises from 270 C to 370 C. The value of ∆ U is
100 kJ
10 kJ
0 kJ
1 kJ

10. An ideal gas is taken around the cycle ABCA as shown in P-V diagram The next work done by the gas during the cycle is equal to:
12P1V1
6P1V1
5P1V1
P1V1

11. In which of the following process, a maximum increase in entropy is observed?
Dissolution of Salt in Water
Condensation of Water
Sublimation of Naphthalene
Melting of Ice

12. The bond energy (in kcal mol-1) of a C-C single bond is approximately
1
10
83-85
1000

13. Which thermodynamic function accounts automatically for enthalpy and entropy both?
Helmholtz Free Energy (A)
Internal Energy (E)
Work Function
Gibbs Free Energy

14. The enthalpies of combustion of carbon and carbon monoxide are -393.5 and -283.0 kJ mol-1 respectively. The enthalpy of formation of carbon monoxide is:
-676 kJ
110.5 kJ
-110.5 kJ
676.5 kJ

15. The amount of the heat released when 20 ml 0.5 M NaOH is mixed with 100 ml 0.1 M HCl is x kJ. The heat of neutralization is
-100 × kJ/mol
-50 × kJ/mol
100 × KJ/mol
50 × kJ/mol

16. Based on the first law of thermodynamics, which one of the following is correct?
For an isothermal process, q = +w
For an isochoric process, ΔU = -q
For an adiabatic process, ΔU = -w
For a cyclic process, q = -w

17. The temperature of the system decreases in an ______.
Adiabatic Compression
Isothermal Expansion
Isothermal Compression
Adiabatic Expansion

18. Which of the following salts will have maximum cooling effect when 0.5 mole of the salt is dissolved in same amount of water. Integral heat of solution at 298 K is given for each salt?
KNO3 (∆H = 35.4 kJ mol-1)
NaCl (∆H = 5.35 kJ mol-1)
HBr (∆H = -83.3 kJ mol-1)
KOH ( ∆H = -55.6 kJ mol-1)

19. Standard enthalpy of vapourisation ΔHvap for water at 100oC is 40.66 kJmol-1. The internal energy of vapourisation of water at 100°C (in kJmol-1) is (Assume water vapour to behave like an ideal gas)
43.76
40.66
37.56
-43.76

20. The solubility of Ca3​(PO4​​)2​ in water is y mol/L. Its solubility product is:
6y²
36 y4
64 y5
108 y5

21. A physician wishes to prepare a buffer solution at pH = 3.85 that efficiently resists changes in pH yet contains only small concentration of the buffering agents. Which of the following weak acids together with its sodium salt would be best to use?
2, 5-Dihydroxy benzoic acid (pKa = 2.97)
Acetoacetic acid (pKa = 3.58)
m-Chlorobenzoic acid (pKa = 3.98)
p-Chlorocinnamic acid (pKa = 4.41)

22. What is the pH of a 0.10 M solution of barium hydroxide, Ba (OH)2?
11.31
11.7
13.30
None of these

23. Which of the following oxides is not expected to react with sodium hydroxide?
CaO
SiO2
BeO
B2O3

24. The pH of a 10-10 M NaOH solution is nearest to
10
7
4
-10

25. A weak acid HX has the dissociation constant 1 × 10-5 M. It forms a salt NaX on reaction with alkali. The degree of hydrolysis of 0.1 M solution of NaX is
0.0001%
0.01%
0.1%
0.15%

26. When equal volumes of 0.1 M NaOH and 0.01 M HCl are mixed, the hydroxide ion concentration is
7.0
1.04
12.65
2.0

27. Concentration of the Ag+ ions in a saturated solution of Ag2C2O4 is 2.2 x 10-4 mol L-1. Solubility product of Ag2C2O42 is
2.66 × 10-12
4.5 × 10-11
5.3 × 10-12
2.42 × 10-8

28. In a reversible chemical reaction at equilibrium, if the concentration of any one of the reactants is doubled, then the equilibrium constant will
Also be Doubled
Be Halved
Remain the Same
Become One-Fourth

29. When a neutral atom undergoes oxidation, the atoms oxidation state
Decreases as it gains electrons
Decreases as it loses electrons
Increases as it gains electrons
Increases as it loses electrons

30. Concentration of the Ag-4 ions in a saturated solution of Ag2C2O4 is 2.2 × (a) 10-4 mol L-1. Solubility product of Ag2C2O4 is
2.66 × 10-12
2.42 × 10-8
4.5 × 10-11
5.3 × 10-12

31. Among the following the weakest Bronsted base is
F–
Cl–
Br–
I–

32. A certain buffer solution contains equal concentration of X– and HX. The ka for HX is 10-8. The pH of the buffer is
3
8
11
14

33. Solubility of M2S salt is 3.5 × 10-6 then find out solubility product.
1.7 × 10-6
1.7 × 10-16
1.7 × 10-18
1.7 × 10-12

34. Among the following hydroxides, the one which has the lowest value of Ksp at ordinary temperature (about 25°C ) is
Mg (OH)2
Ca(OH)2
Ba(OH)2
Be(OH)2

35. Which of the following mixtures in aqueous solution of equimolar concentration acts as a buffer solution?
HNO3 and NaOH
H2SO4 and KOH
NH4OH(excess) + HCl
CH3COOH and NaOH(excess)

36. Amines behave as
Lewis Acids
Lewis Base
Aprotic Acid
Neutral Compound

37. The oxidation number of Cl in Cl2O7 is
+ 7
+ 5
+ 3
– 7

38. What is known as Autooxidation?
ormation of H2O by the oxidation of H2O2.
Formation of H2O2 by the oxidation of H2O
Both (1) and (2) are true
None of the above

39. The tendency of an electrode to lose electrons is known as
Electrode Potential
Reduction Potential
Oxidation Potential
E.M.F.

40. If equal volumes of 1M KMnO4 and 1M K2Cr2O7 solutions are allowed to oxidize Fe2+ in acidic medium. The amount of iron oxidized will be:
More with KMnO2
More with K2Cr2O7
Equal with both oxidising agents
Cannot be determined

41. Which of the following processes does not involve either oxidation or reduction?
Formation of slaked lime from quick lime
Heating Mercuric Oxide
Formation of Manganese Chloride from Manganese oxide
Formation of Zinc from Zinc blende

42. One mole of N2H4 loses ten moles of electrons to form a new compound A. Assuming that all the nitrogen appears in the new compound, what is the oxidation state of nitrogen in A? (There is no change in the oxidation state of hydrogen.)
-1
-3
+3
+5

43. How many millilitres of 0.5 M H2SO4 are needed to dissolve 0.5 g of copper(II)carbonate?
6.01
4.5
8.1
11.1

44. The oxidation state of Cr in Cr (CO)6 is
0
2
4
6

45. Which of the following processes does not involve oxidation of iron?
Formation of Fe(CO)5 from Fe.
Liberation of H2 from steam by iron at high temperature.
Rusting of iron sheets.
Decolourisation of blue CuSO4 solution by iron.

46. The number of moles of KMnO4 reduced by one mole of KI in alkaline medium is
One
Two
Five
One fifth.

47. Which of the following reactions does not involve either oxidation or reduction?
VO2+ → V2O3
Na → Na+
CrO2-4 → Cr2O2-7
Zn2+ →Zn

48. KMnO4​ reacts with oxalic acid according to the equation 2MnO4–​ + 5C2​O4​2-​ + 16H+ → 2Mn2+​ +10CO2​ + 8H2​O Here 20 mL of 0.1 M KMnO4​ is equivalent to
50 mL of 0.5 M C2H2O4
20 mL of 0.1 M C2H2O4
20 mL of 0.5 M C2H2O4
50 mL of 0.1 M C2H2O4

49. What is n-factor?
Equal to product of Number of moles of electrons when Lost or gained by one mole of reductant or oxidant
When Number of moles of electrons Lost or gained by one mole of reductant or oxidant is not same.
Equal to Number of moles of electrons Lost or gained by one mole of reductant or oxidant
None of the above

50. The oxidation number of Mn is maximum in
MnO2
K2MnO4
Mn3O4
KMnO4

51. The oxidation process involves
Increase in oxidation number
Decrease in oxidation number
No change in oxidation number
None of the above

52. Metals generally react with dilute acids to produce hydrogen gas. Which one of the following metals does not react with dilute hydrochloric acid?
Copper
Magnesium
Iron
Silver

53. The oxidation number of Xe in BaXeO6 is
8
6
4
10

54. The colourless solution of silver nitrate slowly turns blue on adding copper chips to it because of
Dissolution of Copper
Oxidation of Ag+ → Ag
Reduction of Cu2+ ions
Oxidation of Cu atoms.

55. A standard reduction electrode potentials of four metals are A = -0.250 V, B = -0.140 V, C = -0.126 V, D = -0.402 V The metal that displaces A from its aqueous solution is:
A
B
C
D

56. Pure H2O2 is :
Semi – solid
Liquid
Solid
Gas

57. The freezing point of heavy water is
0°C
3.8°C
4°C
1°C

58. H2O2 used in rocket has the concentration:
50%
90%
70%
30%

59. Which of the following hydrides are generally nonstochiometric in nature?
Ionic Hydrides
Molecular Hydrides
Interstitial Hydrides
All of the Above.

60. What is the product of the reaction of H2O2 with Cl2?
O2 + HOCl
HCl + O2
H2O + HCl
HCl + H2

61. Water shows anomalous behavior between
0 to 4°C
0 to 5°C
0 to -4°C
4 to 0°C

62. Which of the following statements regarding hydrogen peroxide is/ are incorrect?
As aerating agent in production of sponge rubber
As an antichlor
For restoring white colour of blackened lead painting
All of the above

63. Atomic hydrogen is called
Protium
Deutrium
Nascent Hydrogen
Tritium

64. The volume strength of 1.5 NH2O2 solution is :
4.8
5.2
8.8
8.4

65. Water gas is mixture of hydrogen H2 and
CO
CO2
Cl2
SO2

66. Hydrogen has isotopes
2
3
4
5

67. Pure H2O2 is:
Semi – solid
Liquid
Solid
Gas

68. _________________ on water decolourises H2O2
O3
Acidic KMnO4 solution
Black Suspension of Lead Sulphide(PbS)
None of these

69. What is gram equivalent weight of hydrogen peroxide as reductant?
100
125
152
None of the above

70. Hydrogen is the most abundant element on earth after______.
Oxygen
Carbon
Sulphur
None of the above

71. Hydrogen is a good __________ agent.
Oxidizing
Reducing
Acidic
Basic

72. The volume of 10 volume H2O2 required to liberate 500 ml of O2 at S.T.P. is :
25 ml
50 ml
100 ml
125 ml

73. Hydrogen is most __________ element in the universe.
Abundant
None
Both
Consumer

74. CsOH is
Strongly basic
Weakly basic
Slightly acidic
Amphoteric.

75. Alkali metals give a _________________when dissolved in liquid ammonia
Deep blue solution
Colourless
Red colour
None of the above

76. What are Oxo-Acids?
Acid containing Oxygen
Acid containing Sulphur
Acid containing Carbon
None of the above

77. In curing cement plasters, water is sprinkled from time to time. This helps in
Converting sand into silicic acid
Keeping it cool
Developing interlocking needle like crystals of hydrated silicates
Hydrating sand and gravel mixed with cement.

78. The substance not likely to contain CaCO3 is
Dolomite
A marble statue
Calcined gypsum
Sea shells

79. Carnallite is the mineral of:
Na
Ca
Mg
None of the above

80. The wire of flash bulb is made up of:
Mg
Ag
Cu
Ba

81. The basic strength of which hydroxide is maximum
LiOH
NaOH
Ca (OH)2
KOH

82. The composition of Sorels cement is
KCl × MgCl2× 6H2O
MgCl2 × 5MgO × (xH2O)
MgCO3 × CaCO3
CaSO4 × 2H2O

83. Which of the following alkali metals has the least melting point?
Na
K
Rb
Cs

84. The hydration energy of Mg2+ is larger than that of
A13+
Na+
Be26
Mg3+

85. Milk of lime reacts with chlorine to form ________, a constituent of bleaching powder.
Ca(OCI)2
Ca(CIO2)2
Ca(CIO3)2
Ca(CIO4)2