MDCAT Chemistry MCQ #477

When 3.0 g of propanal (C3H6O) is oxidized to propionic acid, what mass of Cu2O is produced? (Molar masses: C3H6O = 58 g/mol, Cu2O = 143 g/mol)

MDCAT Chemistry MCQ #477

  1. Question 1

    Q1. When 3.0 g of propanal (C3H6O) is oxidized to propionic acid, what mass of Cu2O is produced? (Molar masses: C3H6O = 58 g/mol, Cu2O = 143 g/mol)

    • A) 3.73 g
    • B) 2.96 g
    • C) 1.45 g
    • D) 5.80 g

    Answer: 2.96 g

    Explanation: 1 mole of aldehyde produces 1 mole of Cu2O. 3.0 g / 58 g/mol = 0.0517 mol. 0.0517 mol × 143 g/mol = 7.39 g (A fails due to miscalculating stoichiometry).