For the synthesis of ammonia by the reaction `N_(2)+3H_(2)hArr2NH_(3)` in the Haber's process ,the attainment of equilibrium is correctly predicated bt the curve

Options

A.
B.
C.
D.

Answer

To solve the question regarding the synthesis of ammonia in the Haber process and the correct prediction of equilibrium by a graph, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Reaction**: The reaction for the synthesis of ammonia is given by:
\[ N_2 + 3H_2 \rightleftharpoons 2NH_3 \]
This indicates that one mole of nitrogen reacts with three moles of hydrogen to produce two moles of ammonia.

2. **Initial Concentrations**: At the start of the reaction (time \( t_0 \)), only the reactants (nitrogen and hydrogen) are present. Therefore:
- Concentration of \( N_2 \) = \( \frac{A}{V} \) (where \( A \) is the initial moles of \( N_2 \))
- Concentration of \( H_2 \) = \( \frac{B}{V} \) (where \( B \) is the initial moles of \( H_2 \))
- Concentration of \( NH_3 \) = 0

3. **Change in Concentrations at Equilibrium**: As the reaction proceeds towards equilibrium, some of the reactants will be converted into products. Let \( x \) be the amount of \( N_2 \) that reacts:
- Concentration of \( N_2 \) at equilibrium = \( \frac{A - x}{V} \)
- Concentration of \( H_2 \) at equilibrium = \( \frac{B - 3x}{V} \)
- Concentration of \( NH_3 \) at equilibrium = \( \frac{2x}{V} \)

4. **Graph Analysis**: The question asks which graph correctly represents the attainment of equilibrium:
- At \( t_0 \), the concentration of \( NH_3 \) should be zero.
- As the reaction progresses, the concentration of \( NH_3 \) will increase, while the concentrations of \( N_2 \) and \( H_2 \) will decrease.
- At equilibrium, the concentrations of all species will remain constant.

5. **Identifying the Correct Graph**: The correct graph should show:
- \( NH_3 \) starting from zero and increasing until it reaches a constant value.
- \( N_2 \) and \( H_2 \) starting from their initial concentrations and decreasing until they reach constant values at equilibrium.

6. **Conclusion**: Based on the analysis, the graph that shows \( NH_3 \) starting from zero and increasing, while \( N_2 \) and \( H_2 \) decrease and then stabilize, is the correct representation of the equilibrium state in the Haber process.

### Final Answer:
The correct option is **A**, as it accurately depicts the changes in concentrations during the attainment of equilibrium in the Haber process.

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