Dehydration of Alcohols to Alkenes

Steps:

• Identify the product: propene (C3H6, an alkene) from propan-1-ol (C3H7OH, a primary alcohol).
• Recall reaction types: alcohols undergo dehydration (elimination of H2O) to form alkenes under acidic conditions with heat.
• Match to options: only dehydration links propan-1-ol directly to propene via loss of water.
• Eliminate mismatches: other options produce different products or reverse reactions.

Why C is correct:

• Dehydration of propan-1-ol follows the general formula R-CH2-CH2-OH → R-CH=CH2 + H2O, yielding propene (CH3CH=CH2) by E1 mechanism in acid.

Why the others are wrong:

• A: Addition reactions involve alkenes gaining groups; 1-chloropropane forms from substitution, not addition to alcohol.
• B: Complete combustion of propan-1-ol yields CO2 and H2O (C3H7OH + 9/2 O2 → 3CO2 + 4H2O), not CO.
• D: Reduction of propan-1-ol yields propane (alkane); propanal forms by oxidation, not reduction.

Final answer: C