Solvent dictates substitution vs. elimination for bromoethane with NaOH

Steps:

• Bromoethane (CH₃CH₂Br) reacts with NaOH via SN2 in protic water, yielding substitution product ethanol (CH₃CH₂OH).
• In ethanolic NaOH, the less polar solvent promotes E2 elimination, yielding ethene (CH₂=CH₂).
• Evaluate row 1: ethanolic solvent should give ethene, not ethane-1,2-diol (HOCH₂CH₂OH), so incorrect.
• Evaluate rows 2 and 3: aqueous solvent favors substitution to ethanol, not elimination to ethene, so row 2 correct, row 3 incorrect.

Why C is correct:

• C identifies only row 2 as accurate, aligning with the rule that aqueous NaOH drives nucleophilic substitution per SN2 mechanism for primary alkyl halides.

Why the others are wrong:

• A includes row 1, but ethanolic NaOH yields ethene via E2, not diol.
• B includes row 1, ignoring elimination in ethanol.
• D includes row 3, but water favors substitution, not E2 elimination.

Final answer: C