Pentaerythritol's alcohol groups determine its reactivity

Steps:

• Identify pentaerythritol's structure: C(CH₂OH)₄ with four primary alcohol groups and formula C₅H₁₂O₄.
• Evaluate option D: Each -OH group reacts with Na to form ½ mole H₂, so four groups yield 2 moles H₂ per mole of compound.
• Check option B: Empirical formula CH₂.₄O (simplest ratio) matches molecular C₅H₁₂O₄ after scaling.
• Assess options A and C: Dehydration favors ether formation in polyols; alcohols oxidize with KMnO₄(VII).

Why D is correct:

• Alcohols follow ROH + Na → RONa + ½H₂, so tetrol C(CH₂OH)₄ produces 2 moles H₂ from four -OH groups.

Why the others are wrong:

• A: Polyols like pentaerythritol dehydrate to ethers with H₂SO₄, not alkenes.
• B: Empirical and molecular formulas are identical (C₅H₁₂O₄).
• C: Primary alcohols in pentaerythritol oxidize to carboxylic acids with acidified KMnO₄(VII).

Final answer: D