SN1 Favors Tertiary Haloalkanes in Polar Protic Solvents

Steps:

• Classify each haloalkane by carbon type: primary (1°), secondary (2°), or tertiary (3°).
• SN1 requires carbocation intermediate, stable only for 3° carbons in polar protic solvents like water.
• Aqueous NaOH is polar protic, promoting SN1 for 3° but SN2 for 1° and 2° haloalkanes.
• Select the 3° haloalkane option as it proceeds mainly by SN1.

Why C is correct:

• Option C is a tertiary haloalkane, forming a stable tertiary carbocation per Markovnikov stability rules.

Why the others are wrong:

• A: Primary haloalkane; steric hindrance low, favors SN2 backside attack.
• B: Secondary haloalkane; balanced but prefers SN2 in protic solvent with good nucleophile.
• D: Aryl or vinylic haloalkane; sp² carbon prevents carbocation formation, no SN1.

Final answer: C