1. In the equilibrium reaction involving the dissociation of \[CaCO_{3}\]

\[CaCO_{3}\left(s\right)\rightleftharpoons CaO\left(s\right)+CO_{2}\left(g\right)\]

the equilibrium constant is given by

a) \[\frac{p_{CaO}*p_{CO_{2}}}{p_{CaCO_{3}}}\]

b) \[C_{CaO}*\frac{p_{CO_{2}}}{C_{CaCO_{3}}}\]

c) \[\frac{p_{CaO}}{p_{CaCO_{3}}}\]

d) \[p_{CO_{2}}\]

Explanation: K

_{p}= \[p_{CO_{2}}\] others are solids. The concentration terms for solids and liquids are taken as unity

2. Steam reacts with iron at high temperature to give hydrogen gas and \[Fe_{3}O_{4}\left(s\right)\] . The correct expression for the equilibrium constant is

a) \[\frac{P_{H_{2}}^2}{P_{H_{2}O}^2}\]

b) \[\frac{\left(P_{H_{2}}\right)^{4}}{\left(P_{H_{2}O}\right)^{4}}\]

c) \[\frac{\left(P_{H_{2}}\right)^{4}\left[Fe_{3}O_{4}\right]}{\left(P_{H_{2}O}\right)^{4}\left[Fe\right]}\]

d) \[\frac{\left[Fe_{3}O_{4}\right]}{\left[Fe\right]}\]

Explanation:

3. In lime kiln, the reversible reaction

\[CaCO_{3}\left(s\right)\rightleftharpoons CaO\left(s\right)+CO_{2}\left(g\right)\]

proceeds to completion because

a) of high temperature

b) \[CO_{2}\] escaped out

c) CaO is removed

d) of low temperature

Explanation: Forward reaction is favoured by removal of products

4. If 1.0 mole of \[I_{2}\] is introduced into 1.0 litre flask at 1000 K, at quilibrium \[\left(K_{C}=10^{-6}\right)\] , which one is correct

a) \[\left[I_{2}\left(g\right)\right]>\left[I^{-}\left(g\right)\right]\]

b) \[\left[I_{2}\left(g\right)\right]<\left[I^{-}\left(g\right)\right]\]

c) \[\left[I_{2}\left(g\right)\right]=\left[I^{-}\left(g\right)\right]\]

d) \[\left[I_{2}\left(g\right)\right]=\frac{1}{2}\left[I^{-}\left(g\right)\right]\]

Explanation:

5. At equilibrium, if\[K_{P}=1\] , then

a) \[\triangle G^{\circ}=0\]

b) \[\triangle G^{\circ}>1\]

c) \[\triangle G^{\circ}<1\]

d) None of these

Explanation:

6. Van't Hoff's equation giving the effect of temperature on chemical equilibrium is represented as

a) \[\frac{d In F}{dT}=\frac{\triangle H}{RT^{2}}\]

b) \[\frac{d ln K_{P}}{dT}=\frac{\triangle HT^{2}}{R}\]

c) \[\frac{d ln K_{P}}{dT}=\frac{\triangle H}{RT^{2}}\]

d) \[\frac{d ln K_{P}}{dT}=\frac{RT^{2}}{\triangle H}\]

Explanation:

7. Solubility of a substance which dissolves with a decrease in volume and absorption of heat will be favoured by

a) high P and high T

b) low P and low T

c) high P and low T

d) low P and high T

Explanation: high P and high T

8. In what manner will increase of pressure affect the following equation?
\[C\left(s\right)+H_{2}O\left(g\right)\rightleftharpoons CO\left(g\right)+H_{2}\left(g\right)\]

a) Shift in the forward direction

b) Shift in the reverse direction

c) Increase in the yield of hydrogen

d) No effect

Explanation: Reverse reaction, Le Chatelier's principle \[\triangle\]n=2 – 1 = 1.

9. In a reaction, \[A + 2B\rightleftharpoons 2C\] , 2.0 mole of 'A', 3.0 mole of 'B' and 2.0 mole of 'C' are placed in a 2.0 L flask and the equilibrium concentration of 'C' is 0.5 mole/L. The equilibrium constant (K) for the reaction is

a) 0.073

b) 0.147

c) 0.05

d) 0.026

Explanation:

10. 4.5 moles each of hydrogen and iodine were heated in a sealed ten litre vessel. At equilibrium 3 moles of HI were found. The equilibrium constant of

\[H_{2}\left(g\right)+I_{2}\left(g\right)\rightleftharpoons 2HI\left(g\right)\]

a) 1

b) 10

c) 3

d) 0.33

Explanation: