Which pair of electrolytes cannot be distinguished by the products of electrolysis using inert electrodes?

Options

A. 1 M `CuSO_(4)` solution, 1 M `CuCl_(2)` solution
B. 1 M KC1 solution, 1 M KI solution
C. 1 M `AgNO_(3)` solution, 1 M Cu`(NO_(3) )_( 2)` solution
D. 1 M KC1 solution, 1 M NaCl solution

Answer

To determine which pair of electrolytes cannot be distinguished by the products of electrolysis using inert electrodes, we need to analyze the electrolysis of the given electrolytes.

### Step-by-Step Solution:

1. **Identify the Electrolytes**: The question mentions two pairs of electrolytes, specifically KCl (potassium chloride) and NaCl (sodium chloride).

2. **Understand Electrolysis**: During electrolysis, an electric current is passed through an electrolyte, causing chemical reactions at the electrodes. Inert electrodes (like platinum or graphite) do not participate in the reaction but allow the passage of current.

3. **Electrolysis of KCl Solution**:
- At the cathode (negative electrode), water is reduced to hydrogen gas:
\[ 2H_2O + 2e^- \rightarrow H_2 + 2OH^- \]
- At the anode (positive electrode), chloride ions are oxidized to chlorine gas:
\[ 2Cl^- \rightarrow Cl_2 + 2e^- \]

4. **Electrolysis of NaCl Solution**:
- At the cathode, similar to KCl, water is reduced to hydrogen gas:
\[ 2H_2O + 2e^- \rightarrow H_2 + 2OH^- \]
- At the anode, sodium ions do not oxidize; instead, chloride ions are again oxidized to chlorine gas:
\[ 2Cl^- \rightarrow Cl_2 + 2e^- \]

5. **Comparison of Products**:
- For both KCl and NaCl solutions, the products of electrolysis are:
- Hydrogen gas (H₂) at the cathode
- Chlorine gas (Cl₂) at the anode

6. **Conclusion**: Since both KCl and NaCl produce the same gases (H₂ and Cl₂) during electrolysis using inert electrodes, they cannot be distinguished based on the products formed.

### Final Answer:
The pair of electrolytes that cannot be distinguished by the products of electrolysis using inert electrodes is **KCl and NaCl**.

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