​Which of the following aqueous solutions undergoes electrolysis to form sodium hydroxide?​

Correct option is A

The correct answer is (a) NaCl

Explanation:

• Electrolysis of NaCl Solution (Brine):
• When an aqueous solution of NaCl (brine) is electrolyzed, the following reactions occur:

At the cathode (negative electrode):

• 2H₂O(l) + 2e⁻ → H₂(g) + 2OH⁻(aq)

At the anode (positive electrode):

• 2Cl⁻(aq) → Cl₂(g) + 2e⁻

Overall Reaction:

• 2NaCl(aq) + 2H₂O(l) → 2NaOH(aq) + H₂(g) + Cl₂(g)

Why other options don't produce NaOH:

• Na₂SO₄: Electrolysis of Na₂SO₄ primarily produces hydrogen gas at the cathode and oxygen gas at the anode.
• NaHCO₃: Electrolysis of NaHCO₃ can lead to the formation of various products depending on the conditions, but NaOH is not a major product.
• Na₂O: Na₂O is a solid compound and does not undergo electrolysis in aqueous solution.

Therefore, the electrolysis of an aqueous NaCl solution is a common industrial method for producing sodium hydroxide (NaOH).