A reversible reaction is said to have attained equilibrium, when

1. Backward reaction stops

2. Both backward and forward reactions take place at equal speed

3. Both backward and forward reactions stop

4. Concentration of each of the reactants and products becomes equal

In what manner will increase of pressure affect the following equation?

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

1. Shift in the reverse direction

2. Shift in the forward direction

3. Increase in the yield of hydrogen

4. No effect

Which of the following statements is correct regarding the equilibrium between water and its vapour in an open vessel?

1. Equilibrium can be established

2. It depends on pressure conditions

3. Equilibrium cannot be established

4. It depends on temperature conditions

Which of the following equilibrium, in gaseous phase, would be unaffected by an increase in pressure?

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

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

3. ${\mathrm{N}}_2{\mathrm{O}}_4\rightleftharpoons 2{\mathrm{NO}}_2$

4. ${\mathrm{CO}}_2+\frac{1}{2}{\mathrm{O}}_2\rightleftharpoons {\mathrm{CO}}_2$

A saturated solution of non-radioactive sugar was taken and a little radioactive sugar was added to it. A small amount of it gets dissolved in solution and an equal amount of sugar was precipitated. This proves:

1. The equilibrium has not been established in the solution.

2. Radioactive sugar can displace non-radioactive sugar from its solution.

3. Equilibrium is dynamic in nature.

4. None of the above

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

 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

If for the reaction given below

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

find K₃ for the reaction $\frac{1}{2}{\mathrm{P}}_2<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>+<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>\frac{1}{2}{\mathrm{Q}}_2<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>+\frac{1}{2}{\mathrm{R}}_{2<mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>}\rightleftharpoons <mspace\; width="1em"></mspace><mspace\; width="1em"></mspace>\mathrm{PQR}$

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