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?
\({ Ag }_{ 2 }O(s)+2HN{ O }_{ 3 }(aq)\rightleftharpoons 2{ Ag }NO_{ 3 }(aq)+{ H }_{ 2 }O(l)\)

2

(a)

Which of the following reactions involve homogeneous equilibrium and which involve heterogeneous equilibrium?
\(2SO_{ 2 }(g)+O_{ 2 }(g)\rightleftharpoons 2SO_{ 3 }(g)\)

2

(a)

Explain why pure liquids and solids can be ignored while writing the value of equilibrium constants.

2

(a)

The ester, ethyl acetate is formed by the reaction of ethanol and acetic acid and the equilibrium is represented as;
CH₃COOH(l) + C₂H₅OH(l) ⇌ CH₃COOC₂H₅(l) + H₂ O(l)
Write the concentration ratio (concentration quotient) Q for this reaction. Note that water is not in excess and is not a solvent in this reaction.

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 Kc for the reaction PCl_s .= PCl₃ + Cl₂

2

(a)