When two reactants A and B are mixed to give products C and D, the reaction quotient Q, at the initial stages of the reaction

1. is zero

2. decreases with time

3. is independent of time

4. increases with time

A vessel at equilibrium, contains SO₃, SO₂ and O₂. Now some helium gas is added, so that total pressure increasese while temperature and volume remain constant. According to Le Chatelier's Principle, the dissociation of SO₃ 

1. Decreases

2. Remains unaltered

3. Increases

4. Change unpredictably

A chemical reaction is catalysed by a catalyst X. Hence, X

1. Increases activation energy of the reaction

2. Does not effect equilibrium constant of the reaction

3. Decreases rate constant of the reaction

4. Reduces enthalpy of the reaction

If for the reaction given below

$\underset{\mathrm{g}}{2\mathrm{PQ} }\rightleftharpoons \underset{\mathrm{g}}{ {\mathrm{P}}_2 }+\underset{\mathrm{g}}{ {\mathrm{Q}}_2 ; }{\mathrm{K}}_1=2.5\times {10}^5$
$\underset{\mathrm{g}}{\mathrm{PQ} }+ \frac{1}{2}\underset{\mathrm{g}}{{\mathrm{R}}_2 }\rightleftharpoons \underset{\mathrm{g}}{\mathrm{PQR}; }{\mathrm{K}}_2=5\times {10}^{-3}$

find K₃ for the reaction $\frac{1}{2}{\mathrm{P}}_2 + \frac{1}{2}{\mathrm{Q}}_2 +\frac{1}{2}{\mathrm{R}}_{2 }\rightleftharpoons \mathrm{PQR}$

1. $2.5\times {10}^{-3}$

2. $2.5\times {10}^3$

3. $1\times {10}^{-5}$

4. $5\times {10}^{-3}$

For equilibrium reaction

$\mathrm{}$
2NO₂(g) ⇌ N₂O₄(g) + 14.6 J, increase in temperature would

1. Favour the formation of N₂O₄

2. Stop the reaction

3. Favour the decomposition of N₂O₄

4. Not alter the equilibrium

Which of the following favours the backward reaction in a chemical equilibrium?

1. Decreasing the pressure of  the reaction

2. Increasing the concentration of one of the reactants

3. Increasing the concentration of one or more of the products

4. Removal of at least one of the products at regular intervals

In the reaction ${\mathrm{H}}_2+{\mathrm{I}}_2\rightleftharpoons 2\mathrm{HI}$ at equilibrium, some I₂ is added. What happens to the equilibrium?

1. It gets shifted to the right

2. It remains unchanged

3. It gets shifted to the left

4. First 2 then 3

Which of the following reaction will be favoured at low pressure?

1. ${\mathrm{N}}_2+3{\mathrm{H}}_2\rightleftharpoons 2{\mathrm{NH}}_3$

2. ${\mathrm{H}}_2+{\mathrm{I}}_2\rightleftharpoons 2\mathrm{HI}$

3. ${\mathrm{PCl}}_5\rightleftharpoons {\mathrm{PCl}}_3+{\mathrm{Cl}}_2$

4. ${\mathrm{N}}_2+{\mathrm{O}}_2\rightleftharpoons 2\mathrm{NO}$

For the reaction

${\mathrm{PCl}}_5\left(\mathrm{g}\right)\rightleftharpoons {\mathrm{PCl}}_3\left(\mathrm{g}\right)+{\mathrm{Cl}}_2\left(\mathrm{g}\right)$

the forward reaction at constant temperature is favoured by

A. introducing an inert gas at constant volume

B. introducing chlorine gas at constant volume

C. introducing an inert gas at constant pressure

D. increasing the volume of the container

E. introducing PCl₅ at constant volume

1. A, B, C

2. D, E, C

3. B, C, E

4. A, D, E

For the reaction

$\mathrm{CO}\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)\rightleftharpoons {\mathrm{CO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)$

at a given temperature, the equilibrium amount of ${\mathrm{CO}}_2\left(\mathrm{g}\right)$ can be increased by

1. Adding a suitable catalyst

2. Adding an inert gas

3. Decreasing the volume of the container

4. Increasing the amount of CO (g)