Chemical Kinetics

The equilibrium constant is calculated by using the equilibrium concentrations of the reactants and products. Since the total pressure is and the partial pressures are proportional to the amounts of gas, the equilibrium constant is calculated to be 0.80 P.

According to the Arrhenius equation , increasing temperature increases the value of rate constant exponentially.

Adding more hydrogen peroxide (0.1 mol dm ) would increase the concentration of the reactant, leading to a faster rate of reaction, which would result in a higher volume of oxygen produced over time, as shown by curve Y.

A catalyst speeds up a reaction by lowering the activation energy, thus increasing the rate of both the forward and reverse reactions.
However, it does not affect the overall enthalpy change (ΔH) of the reaction because it does not change the reactants or products, just the pathway of the reaction.

For reversible reactions involving gases, the relationship between the equilibrium constants in terms of concentration and pressure is given by: where is the change in the number of moles of gas between products and reactants.
This is derived from the ideal gas law.
In the given options, is correctly related to in option (b), which is a simplified form of the correct relationship.
Thus, the correct answer is (b).

A catalyst is a substance that speeds up a chemical reaction without being consumed in the reaction.
In this case, chlorine (Cl) appears in both the reactants and products without being consumed, indicating that it acts as a catalyst.

The effect of temperature on equilibrium depends on whether the reaction is exothermic or endothermic.
According to Le Chatelier’s Principle, if the reaction is exothermic, increasing the temperature will shift the equilibrium to the left.
If it is endothermic, increasing the temperature will shift the equilibrium to the right.
Therefore, the direction cannot be determined without additional information.

The rate law is given by , where is the rate constant, and and are the concentrations of reactants A and B, respectively.

When the concentration of A is halved, the term decreases by a factor of 4 because the square of a halved concentration is . This causes the rate of the reaction to become of the original rate.

To maintain the same rate, the concentration of B must be increased to compensate for the decrease in . Since the rate is directly proportional to , the concentration of B must be doubled to counteract the reduction in and keep the rate constant.

Therefore, to maintain the same rate, the concentration of B must be doubled.

From the given data for the reaction, we can see that as the concentration of increases, the rate of the reaction changes significantly. The rate depends more on than on , and the best fit to the data suggests that the rate is proportional to the square of the concentration of . Hence, the correct rate expression is .

Increasing the temperature generally increases the rate constant of a reaction, as per the Arrhenius equation, which shows that the rate constant increases exponentially with temperature. This leads to an increased rate of reaction. Thus, the correct answer is (b).