Statement I: In a zero-order reaction, the conc. versus time graph is a straight line

Statement II: The rate change of concentration per unit time in zero-order reaction remains constant

Statement I and statement II are correct and statement II is correct explanation of statement I

The correct answer is Statement I and statement II are correct and statement II is the correct explanation of statement I.

Statement I is correct because, in a zero-order reaction, the concentration of the reactant decreases linearly with time. This is because the rate of reaction is constant, and the concentration of the reactant decreases at a constant rate.

Statement II is also correct because the rate of reaction in a zero-order reaction is equal to the rate constant of the reaction. The rate constant of a reaction is a characteristic of the reaction itself and does not depend on the initial concentration of the reactants.

Therefore, statement II is the correct explanation of statement I. The concentration versus time graph is a straight line because the rate of reaction is constant.

Here is an example of a zero-order reaction:

A → products

In this reaction, A is the reactant and products are the products of the reaction. The rate of reaction is equal to the rate constant, k, and is independent of the concentration of A.

The concentration versus time graph for this reaction would be a straight line with a negative slope. The slope of the line would be equal to -k. This means that the concentration of A decreases at a constant rate.