Question

Define the following terms:
(a) Pseudo first-order reaction
(b) Half-life period of reaction (\(t_{1/2}\))

Hint:

For pseudo first-order reactions, make sure to identify the reactant in excess that remains effectively constant.

Answer 1

(a) Pseudo first-order reaction: A reaction in which one reactant is in excess, making its concentration constant, while the reaction appears to follow first-order kinetics with respect to the limiting reactant. This happens when the rate of the reaction depends on the concentration of one reactant but can be approximated as a first-order reaction.
(b) Half-life period of reaction (\(t_{1/2}\)): The time required for half of the reactant to be consumed in a reaction. For a first-order reaction, it is independent of the initial concentration. The formula is: \[ t_{1/2} = \frac{0.693}{k} \] Where \(k\) is the rate constant.