Nelson cell is used for the preparation of

Options

A. Slaked lime
B. Baryta
C. Sodium
D. Caustic soda

Answer

**Step-by-Step Solution:**

1. **Understanding Nelson Cell**: The Nelson cell is an electrolytic cell specifically designed for the production of sodium hydroxide (NaOH) from sodium chloride (NaCl) solution.

2. **Electrolysis Process**: In the Nelson cell, a concentrated solution of sodium chloride (brine) is subjected to electrolysis. During this process, electrical energy is used to drive the chemical reaction.

3. **Chemical Reactions**: The electrolysis of brine in the Nelson cell leads to the following key reactions:
- At the anode (positive electrode), chloride ions (Cl⁻) are oxidized to chlorine gas (Cl₂):
\[ 2Cl⁻ \rightarrow Cl₂(g) + 2e⁻ \]
- At the cathode (negative electrode), water is reduced to produce hydrogen gas (H₂) and hydroxide ions (OH⁻):
\[ 2H₂O + 2e⁻ \rightarrow H₂(g) + 2OH⁻ \]

4. **Formation of Sodium Hydroxide**: The hydroxide ions produced at the cathode combine with sodium ions (Na⁺) from the brine solution to form sodium hydroxide (NaOH):
\[ Na⁺ + OH⁻ \rightarrow NaOH \]

5. **Final Product**: The overall result of the electrolysis in the Nelson cell is the production of sodium hydroxide (NaOH), along with chlorine gas (Cl₂) and hydrogen gas (H₂) as by-products.

**Conclusion**: The Nelson cell is primarily used for the preparation of sodium hydroxide (NaOH).

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