The decomposition of phosphine, `PH_3` proceeds according to the following equation:
` 4PH_3 (g) to P_4 (g) + 6H_2 (g)`
It is found that the reaction follows the following rate equation:
Rate `=k[PH_3] `
The half-life of `PH_3 ` is 37.9s at `120^@ `C.
How much time is required for 3/4th of `PH_3` to decompose?

Explanation

To solve the problem regarding the decomposition of phosphine (PH₃), we will follow these steps:

### Step-by-Step Solution:

1. **Identify the Reaction and Rate Law**:
The decomposition of phosphine is given by the reaction:
\[
4PH_3 (g) \rightarrow P_4 (g) + 6H_2 (g)
...