Which of the followingg are correct?

Options

A. Electrolysis of dilute NaOH solution given `H_(2)` at cathode and `O_(2)` at anode.
B. Electrolysis of sulphuric acid (dilute or concentrated) gives `H_(2)` at cathode and `O_(2)` at anode.
C. Electrolysis of aqueous KF solution gives fluorine at the anode
D. oxidation of copper anode occurs in the electrolysis of aqueous copper sulphate solution using solution copper electrodes.

Explanation

To determine which statements are correct regarding electrolysis, we will analyze each statement step by step based on the information provided in the transcript.

### Step-by-Step Solution:

1. **Statement 1: Electrolysis of dilute NaOH solution gives H2 at cathode and O2 at anode.**
- **Analysis:**
- In dilute NaOH, the cathode reaction involves the reduction of water (since the reduction potential of water is higher than that of Na+).
- The reaction at the cathode is:
\[ 2H_2O + 2e^- \rightarrow H_2 + 2OH^- \]
- At the anode, the oxidation of hydroxide ions occurs:
\[ 4OH^- \rightarrow 2H_2O + O_2 + 4e^- \]
- Thus, the products are indeed H2 at the cathode and O2 at the anode.
- **Conclusion:** This statement is **true**.

2. **Statement 2: Electrolysis of dilute and concentrated H2SO4 gives H2 at cathode and O2 at anode.**
- **Analysis:**
- In dilute H2SO4, the cathode reaction is:
\[ 2H^+ + 2e^- \rightarrow H_2 \]
- The anode reaction involves the oxidation of water:
\[ 2H_2O \rightarrow O_2 + 4H^+ + 4e^- \]
- In concentrated H2SO4, the cathode reaction remains the same, but the anode reaction changes. The sulfate ions (SO4^2-) do not oxidize, and instead, the reaction can lead to the formation of peroxydisulfate (S2O8^2-).
- **Conclusion:** This statement is **false** for concentrated H2SO4.

3. **Statement 3: Electrolysis of aqueous KF solution gives fluorine at anode.**
- **Analysis:**
- In aqueous KF, the possible anode reactions include the oxidation of water:
\[ 2H_2O \rightarrow O_2 + 4H^+ + 4e^- \]
- The oxidation of fluoride ions (F-) to fluorine gas (F2) is not favored because water has a higher oxidation potential.
- **Conclusion:** This statement is **false**.

4. **Statement 4: Oxidation of copper occurs at the anode in the electrolysis of aqueous copper sulfate solution using copper electrodes.**
- **Analysis:**
- In the electrolysis of copper sulfate with copper electrodes, the anode reaction involves the oxidation of copper:
\[ Cu \rightarrow Cu^{2+} + 2e^- \]
- The copper ions in the solution (Cu^2+) do not oxidize further, as they are already in a higher oxidation state.
- **Conclusion:** This statement is **true**.

### Final Conclusion:
- **True Statements:** 1 and 4
- **False Statements:** 2 and 3