Ncert Exercises & Solutions

True statement among the following is:

1.	The rate of a reaction decreases with the passage of time as the concentration of reactants decreases.
2.	The rate of a reaction is the same at any time during the reaction.
3.	The rate of a reaction is independent of temperature change.
4.	The rate of a reaction decreases with an increase in the concentration of the reactants.

HINT: Rate of reaction depends on temperature.

Explanation:

The rate of reaction is defined as the rate of decrease of concentration of any one of the reactants with the passage of time

$\begin{array}{l} Rate of reaction = \frac{Rate of disappearance of reactant}{Time taken} \\ r = \frac{- d x}{dt} \end{array}$

Thus, as the concentration of reactant decreases with the passage of time, the rate of reaction decreases.