Chlorine reactions with halides, bases, and water

Steps:

• Statement A involves conc. H₂SO₄ + NaCl(s): check if Cl⁻ oxidation occurs.
• Statement B involves Cl₂ + cold NaOH(aq): determine if disproportionation happens.
• Statement C involves Cl₂ + H₂O: assess solution pH change.
• Statement D: identify lack of content.

Why C is correct:

• Chlorine hydrolyzes per Cl₂ + H₂O ⇌ HCl + HOCl, producing H⁺ from HCl, forming an acidic solution.

Why the others are wrong:

• A: Conc. H₂SO₄ displaces HCl from NaCl via NaCl + H₂SO₄ → NaHSO₄ + HCl; Cl⁻ remains reduced, no oxidation.
• B: Cold NaOH yields NaCl + NaClO via Cl₂ + 2NaOH → NaCl + NaClO + H₂O; disproportionation to Cl⁻ and ClO₃⁻ occurs with hot conc. NaOH.
• D: Not enough information.

Final answer: C