Question

The reaction between A₂ (g) and B₂ (g) was carried out in a sealed isothermal container. The rate law for the reaction was found to be:

Rate = \( k[\text{A}_2][\text{B}_2] \)

If 1 mole of A₂ (g) was added to the reaction chamber and the temperature was kept constant, then predict the change in rate of the reaction and the rate constant.

Hint:

Rate constant \( k \) is only affected by temperature, not by the concentration of reactants.

Answer 1

According to the rate law:

Rate = \( k[\text{A}_2][\text{B}_2] \)

When 1 mole of A₂ is added, [A₂] increases. Since the temperature remains constant, the rate constant \( k \) remains unchanged.

Let the initial concentration of A₂ be [A₂], then after adding 1 mole, the new concentration increases, thus increasing the rate proportionally.

Conclusion: The rate of reaction will increase due to increased [A₂], but the rate constant \( k \) remains the same.