Barrons SAT Subject Test Chemistry, 13th Edition

(Marvins-Underground-K-12) #1

  1. (A) Dividing the percentage value, expressed in grams, by the molar mass of
    each element in a compound and then comparing those values provides the
    simplest (or empirical) formula for a compound when expressed in whole
    numbers. Thus, 75 g C ÷ 12 g/mol ≈ 6 mol C, and 25 g H ÷ 1 g/mol ≈ 25 mol
    H. Comparison of the mole values discloses a ratio of about 1 : 4 carbon to
    hydrogen or the empirical formula of CH 4.

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