Assertion `:-` `K_(c)` for process `2H_(2)O(l)hArr2H_(2)O_((g))+O_(2(g))`may be written as `:K_(c)=[H_(2)]^(2)[O_(2)]`
Reason `:-` Concentration of pure liquid is fixed and cannot vary (Taken as `1`)

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertiion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are False

Answer

To solve the question regarding the equilibrium constant \( K_c \) for the process:

\[ 2H_2O(l) \rightleftharpoons 2H_2O(g) + O_2(g) \]

we need to analyze both the assertion and the reason provided.

### Step 1: Write the expression for \( K_c \)

The equilibrium constant \( K_c \) is defined as the ratio of the concentrations of the products to the concentrations of the reactants, each raised to the power of their respective stoichiometric coefficients. For the given reaction, we can express \( K_c \) as follows:

\[ K_c = \frac{[H_2O(g)]^2 [O_2]}{[H_2O(l)]^2} \]

### Step 2: Consider the concentration of pure liquids

In this reaction, \( H_2O(l) \) is a pure liquid. The concentration of a pure substance in its standard state (like a liquid) is considered to be constant and is typically taken as 1. This is because the concentration of a pure liquid does not change during the reaction, as it is not affected by the volume of the container.

### Step 3: Simplify the expression for \( K_c \)

Since the concentration of pure liquid \( H_2O(l) \) is taken as 1, we can simplify the expression for \( K_c \):

\[ K_c = [H_2O(g)]^2 [O_2] \]

This matches the assertion that \( K_c = [H_2]^2 [O_2] \).

### Conclusion

Both the assertion and the reason are true. The assertion correctly states the expression for \( K_c \), and the reason explains why the concentration of pure liquid is taken as 1.

### Final Answer

Both the assertion and the reason are true, and the reason is the correct explanation of the assertion.

---