A first order reaction is 20% complete in 10 minutes. Calculate the period during which 25% of the initial amount remain.
1) 35 min
2) 20 min
3) 62.15 min
4) 40 min

Explanation

To solve the problem, we will follow these steps:

### Step 1: Understand the Reaction
We are dealing with a first-order reaction where 20% of the reactant A is converted to product B in 10 minutes. This means that 80% of A remains after 10 minutes.

### Step 2: Determine the Rate Constant (k)
For a first-order reaction, the integrated rate law is given by:

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