Select correct statement(s) about electrolysis:

Options

A. Electric current is used to drive a non -spontaneous reaction
B. `/_\G` is positive for chemical process during electrolysis
C. Cations and anions are moved toward the anode and cathode respectively
D. Over voltage is generally associated with evolution of `O_2` gas

Answer

To solve the question regarding the correct statements about electrolysis, we will analyze each statement one by one and determine its validity based on our understanding of electrolysis principles.

### Step-by-Step Solution:

1. **Statement 1: Electric current is used to drive a non-spontaneous reaction.**
- **Analysis:** Electrolysis is a process that uses electric current to drive a chemical reaction that would not occur spontaneously. This is a fundamental principle of electrolysis.
- **Conclusion:** This statement is **correct**.

2. **Statement 2: ΔG is positive for chemical processes during electrolysis.**
- **Analysis:** In electrolysis, the cell potential (E_cell) is negative, which indicates that the reaction is non-spontaneous. The relationship between Gibbs free energy (ΔG) and cell potential is given by the equation ΔG = -nFE. Since E is negative, ΔG becomes positive, confirming that the process requires energy input.
- **Conclusion:** This statement is **correct**.

3. **Statement 3: The cations and anions are moved toward the anode and cathode respectively.**
- **Analysis:** In electrolysis, cations (positively charged ions) move towards the cathode (where reduction occurs), and anions (negatively charged ions) move towards the anode (where oxidation occurs). Therefore, this statement is incorrect as it misrepresents the movement of ions.
- **Conclusion:** This statement is **incorrect**.

4. **Statement 4: Overvoltage is generally associated with the evolution of O2 gas.**
- **Analysis:** Overvoltage refers to the extra voltage required beyond the theoretical voltage to drive an electrochemical reaction, particularly during gas evolution reactions. The evolution of O2 gas during electrolysis often requires higher voltage than expected due to kinetic barriers, thus making this statement true.
- **Conclusion:** This statement is **correct**.

### Final Conclusion:
The correct statements about electrolysis are:
- Statement 1: Correct
- Statement 2: Correct
- Statement 3: Incorrect
- Statement 4: Correct

Therefore, the correct statements are 1, 2, and 4.