Empirical and molecular formulae

Empirical and molecular formulae Quiz

Spec 3.1.2.4 · AQA A-Level Chemistry: Quiz

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  1. 1. Which pair has the same empirical formula?

    • A. C₂H₄ and C₄H₈
    • B. C₂H₄ and C₂H₆
    • C. CH₄ and C₂H₄
    • D. C₃H₈ and C₃H₆

  2. 2. A compound contains 40.0% C, 6.7% H and 53.3% O by mass. What is its empirical formula (C = 12.0, H = 1.0, O = 16.0)?

    • A. CHO
    • B. CH₂O
    • C. C₂H₄O
    • D. CH₄O

  3. 3. A sample of an oxide of copper has 0.635 g Cu (Ar 63.5) combined with 0.080 g O (Ar 16.0). What is its empirical formula?

    • A. CuO
    • B. CuO₂
    • C. Cu₂O₃
    • D. Cu₂O

  4. 4. A compound has empirical formula CH₂Cl (mass 49.5) and Mr = 99.0. What is its molecular formula?

    • A. CH₂Cl
    • B. C₃H₆Cl₃
    • C. C₂H₄Cl₂
    • D. C₂H₂Cl₄

  5. 5. The amounts in a compound of X and Y are in the ratio 1 : 1.67 after dividing by the smallest. What is the whole number ratio X : Y?

    • A. 1 : 2
    • B. 2 : 3
    • C. 3 : 5
    • D. 4 : 7

Quiz