Two platinum electrodes were immersed in a solution of `CuSO_(4)` and electric current was passed through the solution. After some time, it was found that colour of `CuSO_(4)` disappeared with evolution of gas at the electrode. The colourless solution contains.

Options

A. Platinum sulphate
B. Copper hydroxide
C. Copper sulphate
D. Sulphuric acid

Explanation

To solve the question regarding the electrolysis of a copper sulfate (CuSO₄) solution using platinum electrodes, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Electrolysis**: When electric current passes through the copper sulfate solution, it causes the ions in the solution to migrate towards the electrodes. The copper ions (Cu²⁺) will move towards the cathode (negative electrode), while the sulfate ions (SO₄²⁻) and water will interact at the anode (positive electrode).

2. **Identifying the Reactions**:
- **At the Cathode**: The Cu²⁺ ions will gain electrons (reduction) to form solid copper (Cu). The reaction can be represented as:
\[ \text{Cu}^{2+} + 2e^- \rightarrow \text{Cu (s)} \]
- **At the Anode**: Water will be oxidized to produce oxygen gas (O₂) and hydrogen ions (H⁺). The reaction can be represented as:
\[ 2\text{H}_2\text{O} \rightarrow \text{O}_2 + 4\text{H}^+ + 4e^- \]

3. **Observing Changes in the Solution**: As the electrolysis proceeds, the blue color of the copper sulfate solution fades. This is because the Cu²⁺ ions are being reduced and deposited as solid copper on the cathode, leading to a decrease in the concentration of Cu²⁺ ions in the solution.

4. **Formation of New Species**: The H⁺ ions produced at the anode combine with the remaining sulfate ions in the solution. This results in the formation of sulfuric acid (H₂SO₄):
\[ \text{H}^+ + \text{SO}_4^{2-} \rightarrow \text{H}_2\text{SO}_4 \]

5. **Conclusion**: The colorless solution that remains after the electrolysis contains sulfuric acid (H₂SO₄) due to the combination of H⁺ ions and SO₄²⁻ ions.

### Final Answer:
The colorless solution contains **sulfuric acid (H₂SO₄)**.

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