NCERT Class 11 Chemistry Equilibrium Very Short Answer Questions

NCERT Class 11 Chemistry Equilibrium Very Short Question And Answers

Question 1. Give examples of two systems involving solid-vapour equilibrium.
Answer:  The equilibrium, solid vapour is found to be established when naphthalene or iodine undergoes sublimation in a closed container.

Question 2. Which of the following is the strongest Bronsted base? CIO^–, ClO₂^–, ClO₃^–, ClO₄^–.
Answer: CIO^– is the strongest Bronsted base

Question 3. The equilibrium established in the evaporation of a liquid at a given temperature is due to the same rate of two processes. What are these two processes?
Answer: The rate of evaporation of the liquid will be equal to the rate of condensation of its vapours at the equilibrium.

Read and Learn More NCERT Class 11 Chemistry Very Short Answer Questions

Question 4. In a soda water bottle, CO₂ gas remains dissolved in water under high pressure. Write down the equilibrium established in this case.
Answer: CO₂(gas) CO₂ (solution)

Question 5. pH of an aqueous 0.1 (M) CH₃COOH solution is 2.87. State whether the pH of the solution will decrease or increase if CH₃COONa is added to this solution.
Answer: pH will increase.

Question 6. Which of the following mixtures will act as buffer solution(s)? 

1. 50 mL 0.1 (M) NH₃ + 100 mL 0.025(M) HCl 
2. 100mL 0.05(M) CH₆COOH + 50mL 0.1 (M) NaOH

Answer: 1. Will act as a buffer solution.

Question 7. At a constant temperature and pressure, what is the value of ΔG for a reaction at equilibrium?
Answer: Zero

Question 8. For a chemical reaction, K_c> 1. Will the value of ΔG° for this reaction be negative or positive?
Answer: Negative

Question 9. Find the relation between K and Kc for the following system: 2NaHCO₃(s) Na₂CO₃(s) + CO₂(g) + H₂O(g)
Answer: K_p=K_c(RT)₂

Question 10. The values of the equilibrium constant for a particular reaction at 25°C and 50°C are 0.08 and 0.12 respectively. State whether it is an exothermic or an endothermic reaction.
Answer: Exothermic

Question 11. If ‘mol-L^-1′ and ‘atm’ are the units of concentration and pressure respectively, then what will be the value of K_p/K_c for the reaction, N₂O₄(g) ⇌ 2NO₂(g) at 300K?
Answer: 24.63L.atmmol^-1

Question 12. Give an example of a reaction for which, K_p = K_c = K_x.
Answer: N₂(g) + O₂(g) ⇌ 2NO(g)

Question 13. Consider the reaction: A(s) + 2B₂(g) ⇌ AB₄(g); ΔH<0. At equilibrium, what would be the effect of increasing temperature on the concentration 
Answer: Increases

Question 14. For the reaction, N₂O₄(g) ⇌ 2NO₂(g) ΔH > 0 Mention two factors whose change at the equilibrium of the reaction will increase Mention two factors whose change at the equilibrium of the reaction will increase the yield of NO₂(g).
Answer: Decrease in temperature, increase in pressure at constant temperature

Question 15. Give an example of a reaction for which, K_p /Kc Is independent of temperature.
Answer: H₂(g) + I₂(g) ⇌ 2HI(g)

Question 16. At a given temperature, if the total pressure of the equilibrium A(s) ⇌ B(g) + C(g) is P, then what is the value of K?
Answer: K_p = P²/2

Question 17. What are the conjugate acid and conjugate base of HPO₄^2-?
Answer:

Conjugate acid: H₂PO₄^–

Conjugate base: PO₄^3-

Question 18. What are the conjugate acid and conjugate base of H₂O?
Answer:

Conjugate acid: H₃O⁺

Conjugate base: OH^–

Question 19. Kb for NH₃ = 1.8 × 10^-5 at 25°C. What is the value of Ka for NH₄ ions at the same temperature?
Answer: 5.55 × 10^-10

Question 20. For pure water, pK_w=12 at a certain temperature. At this temperature, what is the molar concentration of H₂O⁺ In a neutral aqueous solution?
Answer: 10^-6(M)

Question 21. At a certain temperature, pK_w for pure water is 12. At the same temperature, the concentration of H₃O⁺ in aqueous solution is 10^-8 mol L^-1. Is this solution acidic or basic?
Answer: Basic

Question 22. pH of a sample of pure water is x at a certain temperature. Find the value of pK_w at that temperature.
Answer: 2X

Question 23. pK_a values for two acids, HA and HB, are 4 and 6 respectively. Which one is the stronger acid?
Answer: HA

Question 24. pK_a values for two acids, HA, and HB are 4 and 5 respectively. If each of the acid solutions has a concentration of 0.1(M), then in which solution the molar concentration of H₃O⁺ ions is greater?
Answer: HA

Question 25. At 25 °C, pKa for weak acid, HA = x, and pK_b for A^–, the conjugate base of HA = y. Find the value of (x + y) at this temperature.
Answer: (x+y)=14

Question 26. Give examples of two salts, in case of which the pH value of their aqueous solutions is independent of their concentrations.
Answer: CH₃

Question 27. For a weak acid, HA, pK_a = 5. What is the effective range of pH for a buffer comprised of HA and its salt, NaA?
Answer: 4 to 6

Question 28. Give examples of two buffer solutions prepared by mixing two salt solutions of polybasic acid.
Answer: (NaH₂PO_4, Na₂HPO₄)and (NaH₆P₃, Na₂CO₃)

Question 29. In a buffer solution comprising a weak base (B) and its ion (BH⁺), [B] = [BH⁺]. If Kb for the weak base =10^-5, then find the pH value of the buffer solution.
Answer: 9

Question 30. 100 mL of 0.05(M) NaOH solution is added to a 100 mL of 0.1(M) NaH₂PO₄ solution. Will the mixed solution act as a buffer?
Answer: Yes

NCERT Class 11 Chemistry Equilibrium Fill In The Blanks

Question 1. At a given temperature for a reversible reaction, K< 1. The rate constant of the forward reaction is___________________ than that of the reverse reaction.
Answer: Lower

Question 2. If K<1 for a reaction at a particular temperature, then the value ΔG° is___________________
Answer: Positive

Question 3. For a gaseous reaction, K_p > K_c An increase in pressure at constant temperature will ___________________ the product.
Answer: Decrease

Question 4. If C(s) is added the concentration of to the reaction system C(s) + CO₂(g) ⇌ 2CO(g) at constant temperature and volume, then the concentration of CO₂(g) will___________________.
Answer: Remain Unchanged

Question 5. For the reaction, COCl₂(g) ⇌  CO(g) + Cl₂(g); ΔH > 0, an increase in temperature at equilibrium will increase the concentration of___________________
Answer: CO and Cl₂

Question 6. The addition of inert gas to the reaction system, PCl₅(g)⇌ PCl₃(g) + Cl₂(g) at constant___________________does do not affect the state of equilibrium.
Answer: Temperature, Volume

Question 7. At a particular temperature, pKw for pure water =12. Its pH will be___________________
Answer: 6

Question 8. The first and second ionization constants of H2S in its aqueous solution are x and y respectively. So, x is _ than y.
Answer: Greater

Question 9. The conjugate base of [Al(H₂O)₆]³⁺ is___________________.
Answer: [Al(H₂O)₅OH]²⁺

Question 10. The conjugate acid and conjugate base of HPO₂^– are respectively.
Answer: \(\mathrm{H}_2 \mathrm{PO}_4^{-}, \mathrm{PO}_4^{3-}\)

Question 11. At 25°C, in an aqueous solution of HA, Ka for HA = 1(T6. Kb for A+ ion is___________________
Answer: 10^-8

Question 12. If the solubility of Ag3P04 in its saturated aqueous solution is S(M), then, its solubility product will be ___________________
Answer: 27 S⁴

Question 13. The solubility of Ag₂CrO₄ ___________________in an aqueous solution of than its solubility in pure water.
Answer: Lower

Question 14. Addition of CH₃COONa to an aqueous solution of CH₆COOH ___________________AgNO₃ is the pH value.
Answer: Increases