Some `PH_(3)` is introfuced into a flask at `600^(@)C` containing inert gas. `PH_(3)` decomposed to give `P_(4)(g)` and `H_(2)(g)`. The total pressure as a function of time is given below.
`|{:("Time (s)" " "0,60,120,oo),("Pressure (mm) (total) 262.4",272.9,275.53,276.4):}|`
Find the order and half life.

Explanation

To solve the problem of determining the order of the reaction and its half-life, we will follow these steps:

### Step 1: Identify the Reaction Order
The reaction given is the decomposition of phosphine (PH₃) into phosphorus (P₄) and hydrogen (H₂). We need to determine if this reaction follows first-order kinetics.

### Step 2: Write the Rate Constant Expression
For a first-order reaction, the rate constant \( k \) can be expressed using the formula:
\[
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