The half life period of a first order reaction is 60 min. What percentage will be left after 240 min.

Explanation

To solve the problem step by step, we will use the properties of first-order reactions and the concept of half-life.

### Step 1: Understand the half-life of a first-order reaction
The half-life (\( t_{1/2} \)) of a first-order reaction is the time taken for the concentration of the reactant to decrease to half of its initial value. For this problem, the half-life is given as 60 minutes.

### Step 2: Calculate the rate constant (\( k \))
The relationship between half-life and the rate constant for a first-order reaction is given by the formula:
\[
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