For a reaction `N_(2)+3H_(2)hArr2NH_(3)`, the value of `K_(C)` does not depends upon:

Options

A. Initial concentration of the reactants
B. pressure
C. Temperature
D. catalyst

Answer

To determine what the equilibrium constant \( K_c \) for the reaction \( N_2 + 3H_2 \rightleftharpoons 2NH_3 \) does not depend upon, we can analyze the factors that influence \( K_c \).

### Step-by-Step Solution:

1. **Understanding \( K_c \)**:
The equilibrium constant \( K_c \) is defined as the ratio of the concentrations of the products to the concentrations of the reactants at equilibrium, each raised to the power of their coefficients in the balanced equation.

\[ K_c = \frac{[NH_3]^2}{[N_2][H_2]^3} \]

2. **Factors Affecting \( K_c \)**:
- **Concentration**: \( K_c \) is dependent on the concentrations of reactants and products at equilibrium. Thus, it does depend on the equilibrium concentrations.
- **Temperature**: \( K_c \) is also dependent on temperature. According to the Van't Hoff equation, changes in temperature can affect the equilibrium constant.
- **Pressure**: For gaseous reactions, \( K_c \) can be affected by changes in pressure if the number of moles of gas changes. However, the value of \( K_c \) itself is not directly dependent on pressure; it is dependent on the concentrations of the gases at equilibrium.

3. **Catalysts**:
Catalysts speed up the rate of reaching equilibrium but do not change the position of equilibrium or the value of \( K_c \). Therefore, \( K_c \) does not depend on the presence of a catalyst.

4. **Conclusion**:
From the analysis, we can conclude that \( K_c \) does not depend on:
- Initial concentrations of reactants
- Presence of a catalyst

### Final Answer:
The value of \( K_c \) does not depend upon the presence of a catalyst.