Take molar volume = 22.4 dm³/mol. What volume of H₂ at STP is needed to reduce 11.6 g of propanone (M = 58 g/mol) completely to propan-2-ol?

Correct answer C. 4.48 dm³

Explanation

CH₃COCH₃ + H₂ → CH₃CH(OH)CH₃. Moles of propanone = 11.6/58 = 0.20 mol, needing 0.20 mol H₂. Volume = 0.20 × 22.4 = 4.48 dm³.