For the reactions, `N_(2)(g) +3H_(2)(g) rarr 2NH_(3)(g)` predict, whether the work is done on the system or by the system.

Explanation

To determine whether work is done on the system or by the system for the reaction:

\[ N_2(g) + 3H_2(g) \rightarrow 2NH_3(g) \]

we can follow these steps:

### Step 1: Identify the number of moles of gases before and after the reaction.
- **Reactants**:
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