BITSAT Chemistry Equilibrium MCQs

Question: Which of the following can form buffer solution?

a) aq.NH₃ + NH₄OH

b) KOH + HNO₃

c) NaOH + HCl

d) KI + KOH

Answer: aq.NH₃ + NH₄OH

Question: Which of the following can act as both Bronsted acid and Bronsted base?

a) Na₂CO₃

b) OH–

c) HCO₃^–

d) NH₃

Answer: HCO₃^–

Question: The degree of dissociation of PCl₅ (α) obeying the equilibrium  is related to the equilibrium pressure by

a)

b)

c)

d)

Answer:

Question: In a closed system,   if partial pressure of C is doubled, then partial pressure of B will be

a) 2 √2 times the original value

b)

c) 2 times the original value

d)

Answer:

Question: The percentage hydrolysis of 0.15 M solution of ammonium acetate, K_a for CH₃COOH is 1.8 × 10^–5 and K_b for NH₃ is 1.8 × 10^–5

a) 0.556

b) 4.72

c) 9.38

d) 5.56

Answer: 0.556

Question: For a sparingly soluble salt A_pB_q, the relationship of its solubility product Ls→K_sp with its solubility (S) is

a) Ls→K_sp = S^pq (pq)^{P + q}

b) Ls = S^{p + q} .p^pq^q

c) Ls→K_sp = S^{p + q} .p^qq^p

d) Ls→K_sp = S_pqp^pq^q

Answer:  Ls = S^{p + q} .p^pq^q

Question: What is the correct increasing order of Bronsted bases?

a)

b)

c)

d)

Answer:

Question: Which of the following according to Le- Chatelier’s principle is correct?

a) Increase in temperature favours the endothermic reaction

b) Increase in temperature favours the exothermic reaction

c) Increase in pressure shifts the equilibrium in that side in which number of gaseous moles increases

d) All of the above are true

Answer: Increase in temperature favours the endothermic reaction

Question: For a given exothermic reaction, K_p and K ´_P are the equilibrium constants at temperatures T₁ and T₂, respectively. Assuming that heat of reaction is constant in temperature range between T₁ and T₂, it is readily observed that:

a) K_p > K´_P

b) K_p < K ´_P

c) K_p = K´_P

d) 

Answer:  K_p > K´_P

Question: If 1.0 mole of I₂ is introduced into 1.0 litre flask at 1000 K, at quilibrium (K_c = 10^–6), which one is correct?

a) [I₂ (g)] > [I^– (g)]

b) [I₂ (g)] < [I^– (g)]

c) [I₂ (g)] = [I^– (g)]

d)

Answer:

[I₂ (g)] < [I^– (g)]  

Question: For the reaction

 is

a) RT

b) (RT)^–1

c) (RT)^–1/2

d) (RT)^1/2

Answer: (RT)^–1

Question: The pOH value of a solution whose hydroxide ion concentration is 6.2 × 10^–9 mol/litre is

a) 8.21

b) 6.21

c) 7.75

d) 7.21

Answer: 8.21

Question: Which of the following combinations would not result in the formation of a buffer solution?[

a) NH₃ + HCl

b) NH₄Cl + NH₃

c) CH₃COOH + NaCl

d) NaOH+ HC₂H₃O₂

Answer: NaOH+ HC₂H₃O₂

Question: The reaction,  exothermic and reversible. A mixture of SO₂ (g), Cl₂ (g) and SO₂Cl₂ (l) is at equilibrium in a closed container. Now a certain quantity of extra SO₂ is introduced into the container, the volume remaining the same. Which of the following is/are true?

a) The pressure inside the container will not change

b) The temperature will not change

c) The temperature will increase

d) The temperature will decrease

Answer: The temperature will increase

Question: H²S gas when passed through a solution of cations containing HCl precipitates the cations of second group of qualitative analysis but not those belonging to the fourth group. It is because

a) Presence of HCl decreases the sulphide ion concentration.

b) Solubility product of group II sulphides is more than that of group IV sulphides.

c) Presence of HCl increases the sulphide ion concentration.

d) Sulphides of group IV cations are unstable in HCl.

Answer: Presence of HCl decreases the sulphide ion concentration.

Question: The pH of a solution is increased from 3 to 6; its H⁺ ion concentration will be

a) Reduced to half

b) Doubled

c) Reduced by 1000 times

d) Increased by 1000 times

Answer: Reduced by 1000 times

Question: Which of these is least likely to act as Lewis base?

a) F^–

b) BF₃

c) PF₃

d) CO

Answer: BF₃

Question: The K_sp of CuS, Ag₂S and HgS are 10^–31,10^–44 and 10^–54 respectively. The solubility of these sulphides are in the order

a) Ag₂S > CuS > HgS

b) AgS > HgS > CuS

c) HgS > Ag₂S > CuS

d) CuS > Ag₂S > HgS

Answer: Ag₂S > CuS > HgS

Question: If the equilibrium constant of the reaction  then the equilibrium constant for the reaction  would be

a) 1

b) 2

c) 3

d) 4

Answer: 4

Question: For a system in equilibrium, ΔG = 0 under conditions of constant

a) Temperature and pressure

b) Temperature and volume

c) Energy and volume

d) Pressure and volume

Answer: Temperature and pressure

Question: The solubility product of AgCl is 4.0 × 10^–10 at 298 K. The solubility of AgCl in 0.04 M CaCl₂ will be

a) 2.0 × 10^–5 M

b) 1.0 × 10^–4 M

c) 5.0 × 10^–9 M

d) 2.2 × 10^–4 M

Answer: 5.0 × 10^–9 M

Question: What is [H⁺] of a solution having 0.1 M HCN and 0.2 M NaCN? (K_a for HCN = 6.2 × 10^–10)

a) 3.1 × 10¹⁰

b) 6.2 × 10⁵

c) 6.2 × 10^–10

d) 3.1 × 10^–10

Answer: 3.1 × 10¹⁰

Question: When hydrogen molecule decompose into it’s atoms which conditions gives maximum yields of H atoms ?

a) High temperature and low pressure

b) Low temperature and high pressure

c) High temperature and high pressure

d) Low temperature and low pressure

Answer: High temperature and low pressure

Question: If K₁ and K₂ are respective equilibrium constants for the two reactions

the equilibrium constant for the reaction

 will be

a)

b) k₁k₂

c)

d)

Answer:

Question: Which equilibrium can be described as an acidbase reaction using the Lewis acid-base definition but not using the Bronsted-Lowry definition?

a)

b)

c)

d)

Answer:

Question: When H₂S is passed in acidic medium in solution having CuS and ZnS,only CuS is precipitated because

a) K_spZnS = K_spCuS

b) K_spCuS <spZnS

c) K_spCuS >>K_spZnS

d) ZnS has lower melting point than CuS

Answer:  K_spCuS <spZnS

Question: Which of the following according to Le- Chatelier’s principle is correct?

a) Increase in temperature favours the endothermic reaction

b) Increase in temperature favours the exothermic reaction

c) Increase in pressure shifts the equilibrium in that side in which number of gaseous moles increases

d) All of the above are true

Answer: Increase in temperature favours the endothermic reaction

Question: The pH of a solution is increased from 3 to 6; its H⁺ ion concentration will be

a) Reduced to half

b) Doubled

c) Reduced by 1000 times

d) Increased by 1000 times

Answer: Reduced by 1000 times

Question: Which of these is least likely to act as Lewis base?

a) F^– 

b) BF₃

c) PF₃

d) CO

Answer: BF₃

Question: When hydrogen molecule decompose into it’s atoms which conditions gives maximum yields of H atoms ?

a) High temperature and low pressure

b) Low temperature and high pressure

c) High temperature and high pressure

d) Low temperature and low pressure

Answer: High temperature and low pressure