when an aqueous solution of `H_2SO_4` is electrolysed the product at anodes is :

Options

A. `H^-`
B. `OH^-`
C. `SO_4^(2-)`
D. `O_2`

Answer

To determine the product at the anode when an aqueous solution of \( H_2SO_4 \) (sulfuric acid) is electrolyzed, we can follow these steps:

### Step 1: Understand the Electrolysis Process
Electrolysis involves the breakdown of a compound into its components using electricity. In the case of \( H_2SO_4 \), it dissociates into ions in an aqueous solution.

### Step 2: Identify the Ions Present
In an aqueous solution of sulfuric acid, the dissociation can be represented as:
\[ H_2SO_4 \rightarrow 2H^+ + SO_4^{2-} \]
This means we have \( H^+ \) ions, \( SO_4^{2-} \) ions, and water molecules present in the solution.

### Step 3: Determine the Reaction at the Cathode
At the cathode, reduction occurs. The \( H^+ \) ions gain electrons to form hydrogen gas:
\[ 2H^+ + 2e^- \rightarrow H_2 \]
This indicates that hydrogen gas is produced at the cathode.

### Step 4: Determine the Reaction at the Anode
At the anode, oxidation occurs. The hydroxide ions (\( OH^- \)) can be formed from water, and the water molecules can also participate in the reaction. The overall reaction at the anode can be represented as:
\[ 2H_2O \rightarrow O_2 + 4H^+ + 4e^- \]
This indicates that oxygen gas is produced at the anode.

### Step 5: Conclusion
Based on the reactions occurring at both electrodes, the product at the anode during the electrolysis of an aqueous solution of \( H_2SO_4 \) is oxygen gas (\( O_2 \)).

### Final Answer
The product at the anode is \( O_2 \).

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