A first order reaction has a specific rate constant of `2xx10^(-3)s^(-1)` . How much time it will take for20 gm to reduce to 5 g ?

Explanation

To solve the problem of how much time it will take for a first-order reaction to reduce from 20 grams to 5 grams, we can use the first-order reaction formula:

### Step-by-Step Solution:

1. **Identify the Given Values**:
- Initial amount of reactant, \( A_0 = 20 \, \text{g} \)
- Final amount of reactant, \( A_t = 5 \, \text{g} \)
- Rate constant, \( k = 2 \times 10^{-3} \, \text{s}^{-1} \)
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