NCERT Class 11 Chemistry Equilibrium Multiple Choice Questions

NCERT Class 11 Chemistry Equilibrium Multiple Choice Questions

Question 1. Some reactions, their equilibrium constants are as follows:

⇒  \(\mathrm{CO}(\mathrm{g})+\mathrm{H}_2 \mathrm{O}(\mathrm{g}) \rightleftharpoons \mathrm{CO}_2(\mathrm{~g})+\mathrm{H}_2(\mathrm{~g}) ; K_1\)

⇒  \(\mathrm{CH}_4(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{g}) \rightleftharpoons \mathrm{CO}(\mathrm{g})+3 \mathrm{H}_2(\mathrm{~g}) ; K_2 \)

⇒ \(\mathrm{CH}_4(\mathrm{~g})+2 \mathrm{H}_2 \mathrm{O}(\mathrm{g}) \rightleftharpoons \mathrm{CO}_2(\mathrm{~g})+4 \mathrm{H}_2(\mathrm{~g}) ; K_3\)

The relation among K₁, K₂ and K₃ is

1. \(K_3 \times K_2^3=K_1^2\)
2. \(K_1 \sqrt{K_2}=K_3\)
3. K₂ × K₃ = K₁
4. K₃ = k₁ × k₂

Answer: 4. K₃ = k₁ × k₂

Question 2. At a given temperature, the reaction, A(g) 20(g), is In equilibrium In a closed flask. At the same temperature, the reaction, C(g) D(g) + O(g) Is in equilibrium in another closed flask. The values of equilibrium constants of these two reactions are Kp and Kp respectively and the total pressures of the equilibrium mixtures are P₁ and P₂ respectively. If: Kp₂ =1:4 and P₁ P₂ = then the ratio of the degree of dissociation of (g) and C(g) are (assume the degrees of dissociation of body care very small compared to 

1. 0.15
2. 0.5
3. 1.0
4. 1.5

Answer: 2. 0.5

Question 3. At a given temperature, the reaction, A₂(g) + B₂(g) 2A₂(g) was started with 0.4 mol of A₂(g) and 0.0 mol of H₂(g) in a flask of volume 2L. When the reaction achieved equilibrium, it was found that the reaction mixture contained 0.5 mol of AO. (The equilibrium constant ( Kp) for the reaction is

1. 8.30
2. 4.76
3. 10.27
4. 6.49

Answer: 2. 4.76

Question 4. At a given temperature, if the degree of dissociation of N₂O₄ in the following reaction N₂O₄(g) 2NO₂(g) is a, and the total pressure of the equilibrium mixture is P, then it can be shown that the equilibrium constant for the reaction, K_p= a₂P (assuming a is very small compared to 1). Which ofthe following comments is true for this relation

1. K_p increases as a increases
2. K_p increases as P increases.
3. value of Kp does not depend on P but depends on a
4. The value of Kp depends neither on P nor on a

Answer: 4. The value of Kp depends neither on P nor on a

Question 5. For the reactions

⇒ \( \mathrm{N}_2(g)+3 \mathrm{H}_2(g) \rightleftharpoons 2 \mathrm{NH}_3(g),\)

⇒ \(\mathrm{N}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NO}(\mathrm{g}) \& \mathrm{H}_2(\mathrm{~g})+\frac{1}{2}\mathrm{O}_2(\mathrm{~g}) \rightleftharpoons \mathrm{H}_2 \mathrm{O}(\mathrm{g}) \text {, }\)

If the equilibrium constants are K₁, K₂ and K₃ respectively, then the equilibrium constant for the reaction \(4 \mathrm{NH}_3(g)+5 \mathrm{O}_2(\mathrm{~g}) \rightleftharpoons 4 \mathrm{NO}(\mathrm{g})+6 \mathrm{H}_2 \mathrm{O}(\mathrm{g})\) is

1. \(\frac{K_2 K_3^2}{K_1}\)

2. \(\frac{K_2^2 K_3^2}{K_1}\)

3.\(\frac{K_1^3 K_2^2}{K_3}\)

4. \(\frac{K_2^2 K_3^6}{K_1^2}\)

Answer: 4. \(\frac{K_2^2 K_3^6}{K_1^2}\)

Question 6. For a hypothetical reaction, K_c = 0.9 and K_p = 538. Which of the following equations pan represents the reaction properly at 25°C-

1. \(A(g) \rightleftharpoons 2 C(s)+D(g)\)
2. \(B(g) \rightleftharpoons C(l)+D(l)\)
3. \(A(l)+2 B(g) \rightleftharpoons 2 C(g)\)
4. \(A(g)+B(s) \rightleftharpoons 3 C(g)\)

Answer: 4. \(A(l)+2 B(g) \rightleftharpoons 2 C(g)\)

Question 7. When a mixture containing N₂ and H₂ in the molar ratio 1:3 heated in the presence of a catalyst in a closed vessel, die following equilibrium is established:

⇒ \(\mathrm{N}_2(g)+3 \mathrm{H}_2(g) \rightleftharpoons 2 \mathrm{NH}_3(g)\)

At equilibrium, if the mole fraction of NH₃ is 0.6 and the total pressure ofthe equilibrium mixture is 10 atm then Kp for the reaction, \(2 \mathrm{NH}_3(g) \rightleftharpoons \mathrm{N}_2(g)+3 \mathrm{H}_2(g)\)

1. 1.33 atm^-2
2. 0.75 atm^-2
3. 1.333 atm^-2
4. 0.75 atm^-2

Answer: 1. 1.33 atm^-2

Question 8. The reaction, \(A(g)+4 B(g) \rightleftharpoons 2 C(g)+3 D(g)\) is carried out in a closed vessel of volume 2L by taking 3 mol of A(g) and 4 mol of 5(g). At equilibrium, if the amount of C(g) be1 mol, then Kc for the reaction is

1. 0.056
2. 0.038
3. 0.084
4. 1.24

Answer: 3. 0.084

Question 9. The total pressure at the equilibrium of the reaction, XY(g) X(g) + Y(g) is P. If the equilibrium constant P for the reaction is Kp and \(K_p=\frac{P}{8}\), then the percent dissociation of XY is

1. 30.49%
2. 33.33%
3. 41.90%
4. 19.26%

Answer: 2. 33.33%

Question 10. At 500K, for the reaction, PCl₅(g) PCl₃(g) + Cl₂(g) , the equilibrium constant, Kp = 0.52 . In a closed container, these three gases are mixed. If the partial pressure of each of these gases is 1 atm, then in the reaction system.

1. The number of moles of PCl₅ will increase
2. The number of moles of PCl₃ will increase
3. The reaction will attain equilibrium when 50% of the reaction gets completed
4. The reaction will attain equilibrium when 75% of the reaction is completed

Answer: 1. The number of moles of pcl₅ will increase

Question 11. For the reaction: \(2 A(g)+B(g) \rightleftharpoons 3 C(g)+D(g)\), two moles of each A and B were taken into a flask which of the following relation between the concentration terms is true when the system attains equilibrium

1. [A]=[B]
2. [A]<[B]
3. [A]=[B]
4. [A]>[B]

Answer: 2. [A]<[B]

Question 12. The reaction, 2A(g) + 5(g) C(s); ΔH < 0, is in equilibrium in a closed vessel. Which of the following changes at equilibrium’ will increase the yield of C (s)

1. Temperature is increased
2. At constant volume and temperature, some amount of 5(g) is added to the reaction system
3. At constant volume and temperature, some amount of c (s) is removed from the reaction system noriw
4. Pressure is decreased at a constant temperature

Answer: 2. At constant volume and temperature, some amount of 5(g) is added to the reaction system.

Question 13. At 300 K, the reaction A(g) + 5(g) C(s), 1 is in equilibrium in a closed, vessel. At the beginning of the reaction, the partial pressures of A and B gases are 0.2 and 0.3atm respectively and the total pressure of the equilibrium mixture is 0.3atm. Kc, for the reaction, is—

1. 6.06 ×10⁴ L².mol^-2
2. 2.59 × 10³ L².mol^-2
3. 3.03 ×10⁴ L².mol^-2
4. 8.2 ×10² L².mol^-2

Answer: 3. 3.03 × 10⁴ L².mol^-2

Question 14. At 300K, for the reaction, \(\mathrm{AB}_3(\mathrm{~g}) \rightleftharpoons \mathrm{AB}_2(\mathrm{~g})+\frac{1}{2} \mathrm{~B}_2(\mathrm{~g}),\) Kp = 1.66. At the same temperature, ΔG° for the reaction, 2AB₂(g) + B₂(g) 2AB₃(g) is

1. +2.19kJ
2. -2.52KJ
3. +3.85KJ
4. -3.26kJ

Answer: 2. -2.52KJ

Question 15. At a given temperature, when a reversible reaction is carried out in the absence of a catalyst, the ratio of the rate constants for the forward and reverse reactions is found to be 8.0. At the same temperature, if the reaction is carried out in the presence  of a catalyst, then the ratio will be

1. >8.0
2. <8.0
3. =8.0
4. <8.0

Answer: 3. =8.0

Question 16. At a given temperature, a closed vessel contains NH₃ gas and solid NH₄HS. The pressure of NH₃ gas in the vessel is 0.50 atm. On dissociation, NH₄HS produces NH₃ and H₂S gases. The total pressure in the flask at equilibrium is 0.84 atm. The equilibrium constant for the dissociation reaction (Kp) of NH₄HS is

1. 0.30 atm^-2
2. 0.16 atm^-2
3. 0.11 atm^-2
4. 0.22 atm^-2

Answer: 3. 0.11 atm^-2

Question 17. N₂O₄ is dissociated to 33% and 40% at total pressures P₁ and P₂ atm respectively. Hence, the ratio of P₁ to P₂ is

1. \(\frac{7}{3}\)
2. \(\frac{8}{3}\)
3. \(\frac{8}{5}\)
4. \(\frac{7}{4}\)

Answer: 3. \(\frac{8}{5}\)

Question 18. The reaction, A(g) + 25(g) 2C(g) + D(g) was studied using an initial concentration of 5 which was 1.5 times that of. The equilibrium concentrations of A and C were found to be equal. So, Kc for the equilibrium is

1. 4
2. 0.32
3. 2.73
4. 8.17

Answer: 2. 0.32

Question 19. The equilibrium constants Kp₁ and Kp₂ for the reactions x ⇌ 2y and x ⇌ p + q, respectively are in the ratio of 1: 9 . If the degree of dissociation and Z is equal then the ratio of total pressure at this equilibrium is

1. 1:36
2. 1:1
3. 1:3
4. 1:9

Answer: 1. 1:36

Question 20. If the equilibrium constant for Mutrotion or-D-glucose is the percentage ofthe a – form in the equilibrium mixture is

1. 64.5
2. 35.7
3. 53.7
4. 44.8

Answer: 2. 35.7

Question 21. The reaction, C(s) + CO₂(g) ⇌ 2CO(g), is at equilibrium in a closed vessel under a given set of conditions. If the degree of dissociation of CO₂ at equilibrium is a and the total pressure of the equilibrium mixture and the value of equilibrium constant are P and Kp respectively, then a

1. \(\frac{K_p}{\sqrt{2 P}}\)

2. \(\frac{1}{2} \sqrt{\frac{K_p}{p}}\)

3. \(\frac{\sqrt{K_p}}{P}\)

4. \(\sqrt{\frac{P}{K_p}}\)

Answer: 4. \(\sqrt{\frac{P}{K_p}}\)

Question 22. At a given temperature, the equilibrium constant, Kc, for the reaction, A + B C is 10. At the same temperature, the reaction is allowed to occur in a closed vessel of volume 1L. At a particular moment during the reaction, if the amounts of A, B, and C in the reaction system are 0.1, 0.4, and 0.3 mol respectively, then

1. The reaction is in equilibrium at that moment
2. The reaction will occur to a greater extent towards the left to attain equilibrium
3. The reaction will occur to a greater extent towards the right to attain equilibrium
4. The reaction will occur to a greater extent towards the left for achieving equilibrium and concentrations of reactants and product will be the same at a new equilibrium

Answer: 3. The reaction will occur to a greater extent towards the right to attain equilibrium

Question 23. A mixture containing N₂ and H₂ in a mole ratio of 1: 3 is allowed to attain equilibrium when 50% ofthe mixture has reacted. If P is the pressure at equilibrium, then the partial pressure of NH₃ formed is

1. p/3
2. p/2
3. p/9
4. p/5

Answer: 1. p/3

Question 24. If the concentration of OH^– ions in the reaction Fe(OH)₃(s) ⇌ Fe³⁺(aq) + 3OH^–(aq) is decreased by 1/4 times, then equilibrium concentration of Fe³⁺ will be increased by

1. 64 times
2. 4 times
3. 8 times
4. 16 times

Answer: 1. 64 times

Question 25. The equilibrium constant (K_p) for the decomposition of gaseous H₂O, \(\mathrm{H}_2 \mathrm{O}(g) \rightleftharpoons \mathrm{H}_2(g)+\frac{1}{2} \mathrm{O}_2(g)\) is related to degree of dissociation (a ) at a total pressure (P) as-

1. \(\kappa_p=\frac{\alpha^3 p^{1 / 2}}{(1+\alpha)(2+\alpha)^{1 / 2}}\)
2. \(K_p=\frac{\alpha^3 p^{3 / 2}}{(1-\alpha)(2+\alpha)^{1 / 2}}\)
3. \(K_p=\frac{\alpha^{3 / 2} p^2}{(1-\alpha)(2+\alpha)^{1 / 2}}\)
4. \(K_P=\frac{\alpha^{3 / 2} p^{1 / 2}}{(1-\alpha)(2+\alpha)^{1 / 2}}\)

Answer: 4. \(K_P=\frac{\alpha^{3 / 2} p^{1 / 2}}{(1-\alpha)(2+\alpha)^{1 / 2}}\)

Question 26. 2 mol of PCl₅(g) is heated at a given temperature in a closed vessel of volume 2L. As a result, PCl₅(g) dissociates and forms PCl₃(g) and Cl₂(g). When the dissociation reaction reaches equilibrium, it Is found that 50% of PClg(g) has dissociated. Kc for the reaction is

1. 0.15
2. 0.30
3. 0.25
4. 0.5

Answer: 4. 0.5

Question 27. At a given temperature, the reaction, SO₂Cl₂(g) SO₂(g) + CI₂(g), is in a state of equilibrium in a closed vessel. At constant temperature and volume, if some amount of He gas is added to the reaction system, then —

1. The concentration of SO₂(g) will increase
2. The concentration of SO₂Cl₂(g) will increase
3. The concentrations of SO₂(g) , Cl₂(g) , SO₂cl₂(g) will remain the same
4. The value of the equilibrium constant will decrease

Answer: 3. The concentrations of SO₂(g) , Cl₂(g) , SO₂cl₂(g) will remain the same

Question 28. The reaction, C(s) + CO₂(g);⇌2CO(g), is in a state of equilibrium in a closed vessel at a constant temperature. The equilibrium of the reaction will shift towards the left and get re-established if at constant temperature and volume some amount of—

1. C(s) is removed from the reaction system
2. CO₂(g) is added to the reaction system
3. CO₂(g) is removed from the reaction system
4. CO(g) is removed from the reaction system

Answer: 3. CO₂(g) is removed from the reaction system

Question 29. The pair of compounds which cannot exist together in solution is

1. NaHCO₃ and NaOH
2. Na₂CO₃ and NaHCO₃
3. Na₂CO3 and NaOH
4. NaHCO₃ and NaCl

Answer: 1. NaHCO₃ and NaOH

Question 30. Equimolar solutions of the following were prepared in water separately. Which of the solutions will have the highest pH

1. Srcl₂
2. Bacl₂
3. MgC₂
4. Cacl₂

Answer: 2. Bacl₂

Question 31. A student wants to prepare a saturated solution of Ag⁺ ion. He has only three samples of Ag— AgCl (K_sp = 1.8 × 10^-18), AgBr (K_sp = 5 × 10^-13), and Ag₂CrO₄ (K_sp = 2.4 × 10^-12). Which compound should he take’ to obtain maximum [Ag⁺] 

1. Agcl
2. AgBr
3. Ag₂CrO₂₄
4. None of these

Answer: 3. Ag₂CrO₄

Question 32. The correct relationship between the pH of picomolar solutions of sodium oxide (pH₂), sodium sulfide (pH₂), sodium selenide (pH₃), and sodium telluride (pH₄) is

1. pH₁>pH₂>pH₃>pH₄
2. pH₁ <pH₂<pH₃ < pH₄
3. pH₁<pH₂<pH₃<pH₄
4. pH₁>pH₂=pH₃>pH₄

Answer: 1. pH₁>pH₂>pH₃>pH₄

Question 33. Solubility product constant (K_sp) of salts of types MX₁, MX₂ & M₃X at temperature K_sp are 4.0 × 10^-8, 3.2 ×10^-14 & 2.7×10^-13 respectively. Solubilities (mol dm^-3) of the salts at temperature T are in the order—

1. M₃>MX₂>M₃X
2. M₃X>MX₂>MX
3. MX₂>M₃X>MX
4. MX>M₃X>MX₂

Answer: 4. MX>M₃X>MX₂

Question 34. If the solubilities of AgCl in H₂O,0.01(M) CaCl₂ , 0.01(M) NaCl and 0.05(M) AgNO₃ are S₁, S₂, S₂ Ansd S₂ respectively, then—

1. S₁>S₂>S₃>S₄
2. S₁ > S₂ = S₃ > S₄
3. S₁ > s₃ > S₂ > S₄
4. S₄>S₂>S₃>S₁

Answer: 3. S₁ > s₃ > S₂ > S₄

Question 35. The degree of hydrolysis of a salt of weak acid and weak base in its 0.01(M) solution is found to be 50%. If the molarity of the solution is 0.2(M), the percentage hydrolysis of the salt should be

1. 100%
2. 50%
3. 25%
4. 10%

Answer: 2. 50%

Question 36. The first and second dissociation constants of an acid H₂A are 1.0×10^-5 and 5.0×10^-10 respectively. The first and second dissociation constants of an

1. 5.0 ×10^-5
2. 5.0 ×10¹⁵
3. 5.0 ×10^-15
4. 0.2×10⁵

Answer: 3. 5.0 ×10^-15

Question 37. If three salts P₂X, QY₂, and RZ₃ have the same solubilities in water then the correct relation among their Ksp values is—

1. \(K_{s p}\left(\mathrm{P}_2 \mathrm{X}\right)=K_{s p}\left(\mathrm{QY}_2\right)<K_{s p}\left(\mathrm{RZ}_3\right)\)
2. \(K_{s p}\left(\mathrm{P}_2 \mathrm{X}\right)>K_{s p}\left(\mathrm{QY}_2\right)=K_{s p}\left(\mathrm{RZ}_3\right)\)
3. \(K_{s p}\left(\mathrm{P}_2 \mathrm{X}\right)=K_{s p}\left(\mathrm{QY}_2\right)=K_{s p}\left(\mathrm{RZ}_3\right)\)
4. \(K_{s p}\left(\mathrm{P}_2 \mathrm{X}\right)>K_{s p}\left(\mathrm{QY}_2\right)>K_{s p}\left(\mathrm{RZ}_3\right)\)

Answer: 1. \(K_{s p}\left(\mathrm{P}_2 \mathrm{X}\right)=K_{s p}\left(\mathrm{QY}_2\right)<K_{s p}\left(\mathrm{RZ}_3\right)\)

Question 38. The pH of the solution was obtained by mixing 20 mL of 0.01 (M) Ca(OH)₂ and 30 of 0.1 (M) HCl solution is

1. 6.32
2. 9.85
3. 11.3
4. 4.74

Answer: 3. 11.3

Question 39. The pH of an aqueous solution of MCI is 3,0 and that of an aqueous solution of NaOH is 12. The pH of the solution obtained by mixing 100mL of NaOH solution with 500 ml, of HC1 solution’ is

1. 6.71
2. 10.92
3. 12.05
4. 3.08

Answer: 2. 10.92

Question 40. At 25°C, the pH of 0.1(M) aqueous solution of NH₃ is 11.13. At the same temperature, the pH of a ‘solution containing 0.1 (M) of NH₄Cl and 0.01 (M) of NH₃ is-

1. 4.74
2. 6.25
3. 8.26
4. 9.34

Answer: 3. 8.26

Question 41. 800ml. 0.1 (M) HCl solution is mixed with 200ml. 0.5(M) CH₃NH₂ solution. In the resulting solution, traction of H₃O⁺ ions is = fix 10 is

1. 3×10^-5(M)
2. 1.25 ×10^-4(M)
3. 8×10^-11 (M)
4. 7.2×10^-10(M)

Answer: 3. 8 × 10^-11 (M)

Question 42. A solution of a weak acid ( Kn = 10^-5) has a molarity of (M/5). lol of this solution is neutralized completely with a NaOH solution of molarity (M/20). At the neutra¬ lisation point, concentration of H(Of ions (mol-L^-1 ) is

1. 4.39 × 10^-5
2. 1.25 × 10^-6
3. 7.02× 10^-8
4. 1.58 × 10^-9

Answer: 4. 1.58 × 10^-9

Question 43. At 25°C, K for PbCI, is 1.6 × 10^-5 in water. At the same temperature, the amount of PbCl₂ (molar mass = 278.19 g-mol^-`1 ) that remains dissolved in 100 mL of a saturated solution of PbCL, is

1. 0.28g
2. 0.44g
3. 0.17g
4. 0.35g

Answer: 2. 0.44g

Question 44. At 25°C, the solubility product for Gd(OH)₂ in water is 1.2 ×10^-14 What would be the pH of tut aqueous solution of 0.01 (M) Cd²⁺ ions when Cd(OH)₂ starts precipitating

1. 4.29
2. 5.60
3. 8.04
4. 7.56

Answer: 3. 8.04

Question 45. At 25°C the solubility product of a salt AB0 in water is 4.0 × 10^-15 If 0.1 mol of A^2- ions are added to 1 1. of a saturated solution of the salt (assuming the volume of the solution does not change on the addition of A^2- ions), then

1. The solubility product of AB₂ will increase
2. The solubility product of AB₂ will decrease
3. The cone, of b- ions in the solution will be 2 × 10^-7 mol L^-1
4. The solubility of AB₂ in solution will be 4 × 10^-10. mol L^-1

Answer: 3. Cone, of b- ions in solution will be 2 ×10^-7 mol L^-1 

Question 46. At 25°C, Kp for Al(OH)₃.( in water is 2 x 10-33 aqueous solution of ph = 13, the solubility of AI(OH)₃ is 2 ×1 0^-20 . The value of x is

1. 10
2. 15
3. 22
4. 30

Answer: 2. 15

Question 47. At 25°C, K(l for a weak acid, HA in water, is 10- V₂ ml. of 0.1 (M) NaOH solution is added to K, mL of 0.1 (M) solution of HA. How many times would Vl he of K, so that the pH of the solution is 6

1. 2 times
2. 1.5 times
3. 1.1 times
4. 1.4 times

Answer: 3. 1.1 times

Question 48. Which of the relations are correct for the given physical change;

⇒ \(\mathrm{CuSO}_4 \cdot 5 \mathrm{H}_2 \mathrm{O}(\mathrm{s}) \rightleftharpoons \mathrm{CuSO}_4 \cdot 3 \mathrm{H}_2 \mathrm{O}(\mathrm{s})+2 \mathrm{H}_2 \mathrm{O}(\mathrm{g})\) 

1. \(K_p=p_{\mathrm{H}_2 \mathrm{O}}^2\)
2. Kc = [H₂O(g)]₂
3. Kp – K_c(RT)₂
4. Kc = K_p(RT)₂

Answer: 1. \(K_p=p_{\mathrm{H}_2 \mathrm{O}}^2\)

Question 49. At a given temperature, Kc = 6.3 x 10-e for the reaction S-(g) 4S₂(g). At the same temperature, if the lead Ion is started with 2 moles of S0(g) and 0.2 mol of S₂(g) In a closed vessel of volume 1 L, then which of the following comments are true regarding this reaction—

1. At the beginning of the reaction, Q_p = 8.0 × 10^-4 
2. The reaction will occur to a greater extent towards the right To attain equilibrium
3. The reaction will occur to a greater extent towards the left to attain equilibrium
4. The concentration of S₈ at equilibrium is greater than 2 mol. L^-1 

Answer: 1. At the beginning of the reaction, Q_c = 8.0 × 10^-4 

Question 50. 4NH₃(g) + 5O₂(g)⇌4NO(g) + 6H₂O(g), is in equilibrlum In a closed container of volume 1L at a given temperature. If the reaction is started with 1 mol NH₃(g) and 1 mol of O₂(g) and the number of mol of H₂O(g) at equilibrium is 0.6 mol, then at equilibrium-

1. [NH₃] = [NO]
2. [NO]<[O₂]
3. [NO] > [NH₃]
4. [O2] < [H₂O]

Answer: 2. [NO]<[O₂]

Question 51. The reaction, fe(s) + H₂O(g) ⇌ CO(g) + H₂(g); ΔH > 0, is in equilibrium. At equilibrium

1. If the temperature is increased, the partial pressure of H20(g) will decrease
2. The concentration of H₂(g) will decrease if an inert gas is added at constant temperature and volume
3. the concentration of CO(g) will increase if pressure is increased at a constant temperature
4. The equilibrium will move towards the right if an inert gas is added at constant temperature and pressure.

Answer: 1. If the temperature is increased, the partial pressure of H₂O(g) will decrease

Question 52. The reaction, 2NOCl(g)⇌ 2NO(g) + Cl₂(g) ; ΔH>0, Is In equilibrium. Winch of the following changes at equilibrium will decrease The yield of NO(g) —

1. At constant temperature and volume, some amount of nocl(g) is lidded to the reaction system u
2. At constant temperature and volume, some amount of Cl₂(f> ) is added to the reaction system
3. Temperature is decreased at equilibrium
4. At constant temperature and pressure, some airfoil of the gas is added to the reaction system

Answer: 2. At constant temperature and volume, some amount of Cl₂(f> ) is added to the reaction system

Question 53. The vapor density of the equilibrium mixture of NO₂ and N₂O₄ is found to be 40 for the given equilibrium N₂O₄(g) 2NO₂(g). For the given equilibrium

1. 1 Mole percent of nO₂ present in the mixture is 59%
2. 1 Mole percent of nO₂ present in the mixture is 26%
3. The degree of dissociation of n₂O₄ is 0.45
4. The degree of dissociation of n₂O₄ is 0.15

Answer: 2. 1 Mole percent of nO₂ present in the mixture is 26%

Question 54. The vapor pressure of liquid methanol at 50°C is 55.5 kPa. These are correct for the equilibrium reaction attained in a closed vessel of 5 L at 50°C for the following equilibrium CH₃OH(Z) CH₃OH(g)

1. Kp = 55.5kPa
2. Kc = 0.021 mol- L^-1 
3. K = 0.555
4. K = 0.555kPa

Answer: 1. Kp = 55.5kPa

Question 55. The reactions in which the yield of the products cannot be increased by the application of high pressure are—

1. 2SO₂(g) + O₂(g) ⇌2SO₃(g)
2. NH₄HS(s)⇌ NH₃(g) + H₂S(g)
3. N₂O₄(g)⇌2NO₂(g)
4. N₂(g) + 3H₂(g)⇌2NH₃(g)

Answer: 2. NH₄HS(s) NH₃(g) + H₂S(g)

Question 56. Aqueous solutions of which of the following compounds on dilution do not suffer any change in pH value—

1. PhCOONH₄
2. NH₄CN
3. HCOONa

Answer: 1. PhCOONH₄

Question 57. Which can act as an acid as well as a base

1. SO₄^2-
2. HS^–
3. HCO^-3
4. HSO^-4

Answer: 2. HS^–

Question 58. Which mixtures (in molar ratio) can act as buffer

1. H₂CO₃ + NaOH (3:2)
2. H₂CO₃ + NaOH (3: 4)
3. NH₃ + HCl (5: 4)
4. NH₃ + HCl (4: 5)

Answer: 1. H₂CO₃ + NaOH (3:2)

Question 59. If equal volumes of the given solutions are mixed, precipitation of AgCl (Ksp = 1.8 x 10-11) will occur only with

1. 10-4(M)Ag+ and 10-4(M)Cl^–
2. 10-5(M)Ag+ and 10-5(M)Cl^–
3. 10-6(M)Ag+ and 10-6(M)Cr
4. 10-10(M)Ag+ and l0-10(M)Cl^–

Answer: 1. 10-4(M)Ag+ and 10-4(M)Cl^–

Question 60. Which ofthe following is true regarding H₃PO₄

1. Ka = Ka₁ X Ka₂ X Ka₃
2. Ka₁<Ka₂<Ka₃
3. ka₁ >ka₂ > ka₃
4. ka₁=ka₂=ka₂

Answer: 1. Ka = Ka₁ X Ka₂ X Ka₃

Question 61. Select the buffer solutions-

1. 0.8(M) H₂S+0.8(M)KHS
2. 2(M) C₆H₅NH₂+2(M)C₆H₅NH₃Br
3. 3(M)H₂Co₃+3(M)KHCO3
4. 0.05(M) KClO₄+0.05(M) HClO₄

Answer: 1. 0.8(M) H₂S+0.8(M)KHS

Question 62. The solubility Of BaSO₆ will be almost the same in

1. 0.1(M) H2O₄
2. 0.1(M) Ba(OH)₂
3. 0.1(M)BA(NO3)₂
4. 0.2(M) HCl

Answer: 1. 0.1(M) H₂SO₄

Question 63. The special that can act both and as Bronsted adds and as Bronsted base in water are-

1. H₂PO₂-4
2. PO^-3₄
3. HCO₂₃
4. [Fe(H₂O)₆]³⁺

Answer: 1. H₂PO₂

Question 64. Among the following salts, whose aqueous solutions will turn blue litmus paper red-

1. NaHCO₃
2. FeCl₃
3. KCN
4. C₆H₅NH₃Cl

Answer: 2. NaHCO₃

Question 65. At a given temperature, the first and the second ionization constants of the acid, H2A, are 10 × 10^-5 and 5.0 × 10^-10  respectively. Which of the following comments are true regarding this add—

1. The concentration of A²⁺ Ions In 0.01 (M) aqueous solution of  H₂A Js 0,01 (Ml
2. The overall Ionisation constant for H₂A is 5.0 ×10^-15
3. In 0,01 aqueous solution of H₂A, the molar concentration of H30* Ions Is twice that of A²⁺ ions.
4. In 0,01 (M) aqueous solution of H₂A, (H₃O+) ×  [HA-)

Answer: 2. The overall Ionisation constant for H₂A is 5.0 ×10^-15

Question 66. At 25C, Kb for CN^– (the conjugate base of HCN) is 2.5 × 10^-5, If 25rnf, of 0,01 (M) aqueous NaOH solution Is added to 50ml, of0,0 1 (M) HCN solution, then-

1. The pH of the solution is 1 1.2
2. The pH of the respiting solution is 9.4
3. At 20*c, the ionization constant for him is 4 × 10^-18
4. At 23*c, the ionization constant for him is 2.5 × 10^-5

Answer: 2. Ph of the respiting solution is 9.4

Question 67. At a given temperature, If the solubility products for MX, MA_2, and M., B2 In the water are 10^-22, and 10^-33 respectively and their solubilities are S₁, S_2, and S₃ mol-1 respectively, then

1. S₁<S₃
2. S₂>S₃
3. S₂>S₁
4. S₂=S₃

Answer: 1. S₁<S₃

Question 68. At 25-C temperature, the solubility products for BaCrO₄ and SrCrO₄ salts are 2,4 × 10¹⁰ and 3.6 × 10^-6 respectively. If an aqueous solution of K₂CrO₄ is added drop by drop to an aqueous solution containing Ba²⁺ and Sr²₄ ions with concentrations of 10^-4 and 10^-3M) respectively, then—

1. BaCrO₄ will be precipitated first
2. SrCrO₄ will be precipitated first
3. The concentration of sr²⁺ ions will be 6.6 × 10^-8mol-L^-1 when ba²⁺ ions start precipitating
4. The concentration of ba²⁺ ions will be 6.6 × 10^-8 mol-L^-1
5. when sr²⁺ ions start precipitating.

Answer: 1. BaCrO₄ will be precipitated Erst

Question 69. In a buffer solution composed of NaCN and HCN [pKa = 9.4), [NaCN] = 0.2(M) and [HCN] = 0.4(M). An aqueous solution contains Zn²⁺, Ca²⁺, Mn²⁺, and Cr³⁺ ions, each of which has a concentration of 0.1(M). If 500mL of the buffer solution is added to 500mL of this aqueous solution, then the ions that will precipitate in the resulting solution are

1. Zn⁺
2. Ca²⁺
3. Mn²⁺
4. Cr³⁺

Answer: 1. Zn⁺

Question 70. At 25°C, pKb(NH₃) = 4.74, pK_a(HF) = 3.14 and pK_a(HCN) = 9.4. Hence

1. An aqueous solution of nh₄f is acidic
2. Aqueous solution of nh₄cn is acidic
3. The pH of an aqueous solution of nh4cn is greater than that of an aqueous solution of nh4f
4. Ph values of the solutions of both nh4cn and nh4f are independent of the concentrations ofthe solutions

Answer: 1. Aqueous solution of nh4f is acidic

Question 71. Which of the following comments is true

1. If pK_avalues for the acids HA and HB are 4 and 5 respectively, then the concentration of OH- ions in 0.1(M) aqueous solution of HB will be greater than that in 0.1(M) aqueous solution of HA
2. pH of pure water at 0°C is smaller than that at 25°C
3. The degree of hydrolysis of NH₄F in its 0.1 (M) and 0.2(M) aqueous solutions is the same at a particular temperature
4. pH of an acid is 5, implying that the acid is weak.

Answer: 1. If pKa values for the acids HA and HB are 4 and 5 respectively, then the concentration of OH- ions in 0.1(M) aqueous solution ofHB will be greater than that in 0.1(M) aqueous solution of HA

Question 72. A certain buffer solution contains equal concentrations of A- and HA. Kb for A- is 10-10. Hence

1. K_a for HA is 10^-3
2. k_a for HA is 10^-4
3. pH of the buffer is 4
4. PH of the better is 9

Answer: 2. ka for HA is 10-4

Question 73. A buffer solution containing NH3 and NHÿCl has a pH value of 9. pKb for NH3 is 4.7. If in the buffer solution, the total concentration of buffering reagents is 0.6 mol I.-1, then the amount of—

1. NH₃ in the solution is 3.4g.L^-1
2. NH₄C1 in the solution is 8.9g.L^-1
3. NH₄Cl in the solution is 21.4g.L^-1
4. NH₃ in the solution is 17.5g.L^-1

Answer: 1. NH₃ in the solution is 3.4g.L^-1