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 of determining the percentage of a reactant left after a certain time in a first-order reaction, we can follow these steps:

### Step 1: Understand the half-life of the reaction
The half-life (\( t_{1/2} \)) of a first-order reaction is given as 60 minutes. This means that every 60 minutes, half of the reactant will remain.

### Step 2: Determine the rate constant (\( k \))
The half-life for a first-order reaction is related to the rate constant (\( k \)) by the formula:
\[
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