How much volume of 0.1 M HAc should be added to 50 mL of 0.2 M HAc solution if we want to prepare a buffer solution of pH 4.91. Given pK_a for acetic acid is 4.76.

2

(a)

Which of the following reactions involve homogeneous equilibrium and which involve heterogeneous equilibrium?
(i) \({ Ag }_{ 2 }O(s)+2HN{ O }_{ 3 }(aq)\rightleftharpoons 2{ Ag }NO_{ 3 }(aq)+{ H }_{ 2 }O(l)\)
(ii) \(C(s)+CO_{ 2 }(g)\rightleftharpoons 2CO(g)\)
(iii) \(CH_{ 3 }COOC_{ 2 }H_{ 5 }(aq)+{ H }_{ 2 }O(l)\rightleftharpoons CH_{ 3 }COOH(aq)+{ C }_{ 2 }{ H }_{ 5 }OH(aq)\)
(iv) \(2SO_{ 2 }(g)+O_{ 2 }(g)\rightleftharpoons 2SO_{ 3 }(g)\)
(v) \(2Cu\left( { NO }_{ 3 } \right) _{ 2 }(s)\rightleftharpoons 2Cuo(s)+4{ No }_{ 2 }(g)+{ O }_{ 2 }(g)\)
(vi) \({ CH }_{ 3 }COO{ C }_{ 2 }{ H }_{ 5 }(aq)+{ H }_{ 2 }O(l)\rightleftharpoons { CH }_{ 3 }COOH(aq)+{ C }_{ 2 }{ H }_{ 5 }OH(aq)\)
(vii) \({ Fe }^{ 3+ }(aq)+3{ OH }^{ - }(aq)\rightleftharpoons Fe(OH)_{ 3 }(s)\)
(viii) \({ I }_{ 2 }(s)+5{ F }_{ 2 }(g)\rightleftharpoons 2I{ F }_{ 5 }(g)\)

2

(a)

Explain why pure liquids and solids can be ignored while writing the equilibrium constant expression?

2

(a)

What is meant by equilibrium?

2

(a)

State the law of mass action?

2

(a)

Define ionic equilibrium.

2

(a)

What is meant by ionic product of water (k_w) ?

2

(a)

How does a catalyst affect the equilibrium constant?

2

(a)

State Ostwald's dilution law.

2

(a)

SO₃^2- is Bronsted base or acid and why?

2

(a)

(a) In the reaction A + B ⇌ C + D, what will happen to the equilibrium if concentration of A is increased?
(b) The equilibrium constant for a reaction is 2 x 10^-23 at 25^oC and 2 x 10^-2 at 5O°C. Is the reaction endothermic or exothermic?
(c) Mention at least three ways by which the concentration of SO₃ can be increased in the following reaction in a state of equilibrium.

2

(a)

The value of Kc for the reaction 2A ⇌ B + C is 2 x 10^-3. At a given time, thecomposition of reaction mixture is [A] = [B] = [C] = 3 x 10^-4 M. In which direction the reaction will proceed?

2

(a)

PCI_5' PCl₃ and Cl₂ are at equilibrium at 500 K and having concentration 1.59M PCI_3' 1.59M Cl₂ and 1.41M PCl_s' Calculate K_c for the reaction PCl_s ⇌ PCl₃ + Cl₂

2

(a)