**Relation between First and Second Half-Life Period for Zero Order Reaction**

In a chemical reaction, the rate of reaction is often described by its order. The order of a reaction refers to the relationship between the concentration of the reactants and the rate of reaction. A zero order reaction is one in which the rate of reaction is independent of the concentration of the reactants.

The half-life of a reaction is the time it takes for the concentration of a reactant to decrease by half. In the case of a zero order reaction, the half-life is inversely proportional to the initial concentration of the reactant. The relation between the first and second half-life periods for a zero order reaction can be explained as follows:

**First Half-Life Period:**

1. The first half-life period is the time it takes for the concentration of the reactant to decrease by half for the first time.
2. For a zero order reaction, the rate of reaction is constant and independent of the concentration. Therefore, the time taken for the concentration to decrease by half is constant.
3. Mathematically, the first half-life period (t1/2) can be expressed as t1/2 = [A]0 / 2k, where [A]0 is the initial concentration of the reactant and k is the rate constant.

**Second Half-Life Period:**

1. The second half-life period is the time it takes for the concentration of the reactant to decrease by half for the second time.
2. Since the rate of reaction is constant for a zero order reaction, the time taken for the concentration to decrease by half for the second time is the same as the first half-life period.
3. Mathematically, the second half-life period (t2/2) can be expressed as t2/2 = [A]0 / 2k, which is identical to the expression for the first half-life period.

**Relation between First and Second Half-Life Periods:**

1. The relation between the first and second half-life periods for a zero order reaction is that they are equal.
2. This means that the time taken for the concentration of the reactant to decrease by half is constant throughout the reaction.
3. Regardless of the initial concentration, the first and second half-life periods will always be the same for a zero order reaction.
4. This relationship holds true because the rate of reaction is independent of the concentration, resulting in a constant half-life period.

In conclusion, for a zero order reaction, the first and second half-life periods are equal. This is due to the fact that the rate of reaction is constant and independent of the concentration. Understanding the relation between the first and second half-life periods is essential for analyzing and predicting the behavior of zero order reactions.