IR Spectrum Identifies Alcohol via O-H Stretch

Steps:

• Examine 3200-3600 cm⁻¹ region for broad O-H absorption from hydrogen bonding.
• Confirm C-O stretch in 1000-1200 cm⁻¹ for alcohol confirmation.
• Rule out carbonyl C=O at ~1700 cm⁻¹, absent in alcohols.
• Verify C-H stretches ~2900 cm⁻¹ match alkyl chain, no other peaks.

Why C is correct:

• CH3CH2OH shows broad, intense O-H stretch at 3200-3600 cm⁻¹ due to hydrogen bonding in alcohols (IR correlation table).

Why the others are wrong:

• A: Displays sharp C=O stretch at 1710-1715 cm⁻¹ for ketones.
• B: Lacks O-H or C=O; only sharp C-H at 2850-3000 cm⁻¹ for alkanes.
• D: Features both broad O-H and strong C=O at 1700-1710 cm⁻¹ for carboxylic acids.

Final answer: C