MDCAT Chemistry MCQ #478

What volume of H2 gas (at STP) is needed to reduce 4.4 g of propanal to propanol? (Molar mass of propanal = 58 g/mol)

MDCAT Chemistry MCQ #478

  1. Question 1

    Q1. What volume of H2 gas (at STP) is needed to reduce 4.4 g of propanal to propanol? (Molar mass of propanal = 58 g/mol)

    • A) 1.7 L
    • B) 2.2 L
    • C) 3.4 L
    • D) 4.5 L

    Answer: 1.7 L

    Explanation: 1 mole of aldehyde requires 1 mole of H2. 4.4 g / 58 g/mol = 0.0759 mol. 0.0759 mol × 22.4 L/mol = 1.7 L (B overestimates by ignoring 1:1 ratio).