When a dilute aq. Solution of `Li_(2)SO_(4)` is electrolysed, the products formed at the anode and cathode are respectively ?

Options

A. `H_(2) and O_(2)`
B. `O_(2) and Li`
C. `SO_(2) and H_(2)`
D. `O_(2) and H_(2)`

Answer

To determine the products formed at the anode and cathode during the electrolysis of a dilute aqueous solution of lithium sulfate (Li₂SO₄), we can follow these steps:

### Step 1: Ionization of Lithium Sulfate
When lithium sulfate (Li₂SO₄) is dissolved in water, it dissociates into its ions:
\[ \text{Li}_2\text{SO}_4 \rightarrow 2 \text{Li}^+ + \text{SO}_4^{2-} \]

### Step 2: Identify the Electrodes
In electrolysis:
- The **cathode** is the electrode where reduction occurs (gain of electrons).
- The **anode** is the electrode where oxidation occurs (loss of electrons).

### Step 3: Reactions at the Cathode
At the cathode, the lithium ions (\( \text{Li}^+ \)) will gain electrons to form lithium metal. However, in a dilute solution, water is also present, and the reduction of hydrogen ions (\( \text{H}^+ \)) from water is more favorable. The reaction at the cathode can be represented as:
\[ 2 \text{H}_2\text{O} + 2 \text{e}^- \rightarrow \text{H}_2 + 2 \text{OH}^- \]
Thus, hydrogen gas (\( \text{H}_2 \)) is produced at the cathode.

### Step 4: Reactions at the Anode
At the anode, the sulfate ions (\( \text{SO}_4^{2-} \)) can react with water. The oxidation reaction can be represented as:
\[ 2 \text{H}_2\text{O} \rightarrow \text{O}_2 + 4 \text{H}^+ + 4 \text{e}^- \]
Thus, oxygen gas (\( \text{O}_2 \)) is produced at the anode.

### Conclusion
In summary, during the electrolysis of a dilute aqueous solution of lithium sulfate:
- The product formed at the **cathode** is **hydrogen gas (H₂)**.
- The product formed at the **anode** is **oxygen gas (O₂)**.

### Final Answer
The products formed at the anode and cathode are respectively: **Oxygen (O₂) at the anode and Hydrogen (H₂) at the cathode**.

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