Assertion: In cell Current stops flowing when `E_("cell")` = 0.
Reason: Equilibrium of the cell reaction is attained

Options

A. Assertion and Reason both are correct statements and reason is the correct explanation of the assertion.
B. Assertion and Reason both are correct statements, but reason is not the correct explanation of the assertion.
C. Assertion is true, but reason is false.
D. Assertion is false, but reason is true.

Explanation

To solve the question, we need to analyze the assertion and reason provided:

**Assertion:** In a cell, current stops flowing when \( E_{\text{cell}} = 0 \).
**Reason:** Equilibrium of the cell reaction is attained.

### Step-by-Step Solution:

1. **Understanding the Assertion:**
- The assertion states that the current in an electrochemical cell stops when the cell potential \( E_{\text{cell}} \) becomes zero. This implies that there is no driving force for the flow of electrons, which is essential for current.

**Hint:** Consider what happens to the flow of electrons when the potential difference is zero.

2. **Understanding the Reason:**
- The reason provided states that this cessation of current is due to the attainment of equilibrium in the cell reaction. When a cell reaches equilibrium, the forward and reverse reactions occur at the same rate, leading to no net change in concentration of reactants and products.

**Hint:** Think about the relationship between chemical reactions and their equilibrium states.

3. **Linking Assertion and Reason:**
- When equilibrium is reached in an electrochemical cell, the Gibbs free energy change (\( \Delta G \)) becomes zero. The relationship between Gibbs free energy and cell potential is given by the equation:
\[ \Delta G = -nFE_{\text{cell}} \]
- If \( \Delta G = 0 \), then \( E_{\text{cell}} \) must also equal zero, confirming that the assertion is correct.

**Hint:** Recall the equation relating Gibbs free energy to cell potential and think about what it means when \( \Delta G \) is zero.

4. **Conclusion:**
- Both the assertion and the reason are correct, and the reason correctly explains the assertion. Therefore, the answer to the question is that both the assertion and reason are true, and the reason is a correct explanation of the assertion.

**Hint:** Consider how assertions and reasons are evaluated in logical statements.

### Final Answer:
Both the assertion and the reason are correct, and the reason is a correct explanation of the assertion.