What will be the effect on the dissociation of SO₃ when helium gas is added to a system at equilibrium containing
SO₃, SO₂, and O₂, such that total pressure increases while temperature and volume remain constant,
 according to Le Chatelier’s principle?

1. The extent of dissociation decreases

2. The extent of dissociation remains unchanged

3. The extent of dissociation increases

4. The effect cannot be predicted

Identify the correct statement about a catalyst in a chemical reaction:

1. It increases the activation energy of the reaction

2. It does not affect the equilibrium constant of the reaction

3. It decreases the rate constant of the reaction

4. It decreases the enthalpy change of the reaction

Given reactions:

2PQ(g) ⇌ P₂(g) + Q₂(g) ; K₁ = 2.5 × 10⁵

PQ(g) + ½R₂(g) ⇌ PQR(g) ; K₂ = 5 × 10⁻³

Find the equilibrium constant K₃ for the reaction:

½P₂(g) + ½Q₂(g) + ½R₂(g) ⇌ PQR(g)

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)

Which of the following cases leads to the reaction remaining fastest to completion?

1. $\mathrm{K}=1$

2. $\mathrm{K}=10$

3. $\mathrm{K}={10}^{-2}$

4. $\mathrm{K}={10}^2$