Purple hexane layer from iodine presence Steps:

• Halogen reactivity: Cl₂ displaces Br⁻ and I⁻; Br₂ displaces I⁻; I₂ displaces none.
• Purple color in hexane indicates I₂ (from starting I₂ or displacement of I⁻).
• I₂ produced in: Cl₂ + I⁻ and Br₂ + I⁻ (2 cases).
• I₂ present in all three I₂ tests (with Cl⁻, Br⁻, I⁻), regardless of reaction.
• Total: 2 displacements + 3 I₂ tests = 5 purple layers.

Why D is correct:

• Five combinations yield I₂, which colors hexane purple due to its solubility and color in nonpolar solvents.

Why the others are wrong:

• A: Underestimates by ignoring I₂ tests and one displacement.
• B: Accounts for displacements but misses most I₂ tests.
• C: Includes displacements and some I₂ tests but omits one I₂ case.

Final answer: D