For a reaction `N_2+3H_2 hArr 2NH_3` , the value of `K_c` would depend upon

Options

A. initial concentration of the reactants
B. Pressure
C. temperature
D. all of the above

Answer

To determine the factors on which the equilibrium constant \( K_c \) for the reaction \( N_2 + 3H_2 \rightleftharpoons 2NH_3 \) depends, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Equilibrium Constant**: The equilibrium constant \( K_c \) is a numerical value that expresses the ratio of the concentrations of products to the concentrations of reactants at equilibrium. For the given reaction, it is expressed as:
\[ K_c = \frac{[NH_3]^2}{[N_2][H_2]^3} \]

2. **Factors Affecting \( K_c \)**: The equilibrium constant \( K_c \) is influenced by various factors, but primarily it is important to note which factors do not affect it.

3. **Temperature Dependence**: The most crucial factor that affects the value of \( K_c \) is temperature. According to the principles of chemical equilibrium, changing the temperature will change the value of \( K_c \). This is because the equilibrium position shifts in response to temperature changes, especially for endothermic and exothermic reactions.

4. **Independence from Other Factors**: \( K_c \) is independent of:
- The concentrations of reactants and products.
- The presence of catalysts.
- The pressure and volume of the system (for reactions involving gases).

5. **Conclusion**: Therefore, the value of \( K_c \) for the reaction \( N_2 + 3H_2 \rightleftharpoons 2NH_3 \) depends solely on the temperature.

### Final Answer:
The value of \( K_c \) for the reaction \( N_2 + 3H_2 \rightleftharpoons 2NH_3 \) depends on **temperature**.

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