In a chemical reaction
`N_(2)+3H_(2) hArr 2NH_(3)`, at equilibrium point

Options

A. Equal volumes of `N_(2)` and `H_(2)` are reacting
B. Equal masses of `N_(2)` and `H_(2)` are reacting
C. The reaction has stopped
D. The same amount of ammonia is formed as is decomposed into `N_(2)` and `H_(2)`

Explanation

To solve the question regarding the equilibrium of the reaction \( N_2 + 3H_2 \rightleftharpoons 2NH_3 \), we need to analyze the conditions at equilibrium.

### Step-by-Step Solution:

1. **Understanding Equilibrium**: At equilibrium, the rate of the forward reaction (formation of ammonia) is equal to the rate of the backward reaction (decomposition of ammonia back into nitrogen and hydrogen). This means that the concentrations of the reactants and products remain constant over time.

2. **Identifying the Options**: The question provides four options regarding the conditions at equilibrium:
- (A) Equal volumes of \( N_2 \) and \( H_2 \) are reacting.
- (B) Equal masses of \( N_2 \) and \( H_2 \) are reacting.
- (C) The reaction has stopped.
- (D) The same amount of ammonia is formed as is decomposed into \( N_2 \) and \( H_2 \).

3. **Analyzing Each Option**:
- **Option A**: Equal volumes of \( N_2 \) and \( H_2 \) do not guarantee that the reaction will proceed correctly since the stoichiometry of the reaction requires 1 mole of \( N_2 \) for every 3 moles of \( H_2 \).
- **Option B**: Equal masses of \( N_2 \) and \( H_2 \) also do not ensure the correct stoichiometric ratio needed for the reaction to proceed to equilibrium.
- **Option C**: The reaction has not necessarily stopped; it is simply at a state of dynamic equilibrium where the rates of the forward and reverse reactions are equal.
- **Option D**: This option correctly states that at equilibrium, the amount of ammonia formed is equal to the amount of ammonia that decomposes back into \( N_2 \) and \( H_2 \). This reflects the principle of conservation of mass and the definition of equilibrium.

4. **Conclusion**: The correct answer is **Option D**: The same amount of ammonia is formed as is decomposed into \( N_2 \) and \( H_2 \).