IB Chemistry SL 1.4.4 Empirical and Molecular Formulas

Practise deriving the simplest whole-number atom ratio from masses, percentages or combustion products. Convert each element to moles, handle oxygen by mass difference when…

Exam points

convert each element's mass or percentage to moles and simplify the ratio
use product masses or mass gain to account for carbon, hydrogen and oxygen
scale an empirical formula using the ratio of molar mass to empirical-formula mass

[Maximum number: 1]

A hydrocarbon has the empirical formula $\mathrm{C}_{3} \mathrm{H}_{7}$ . When 1.17 g of the compound is heated to $85^{\circ} \mathrm{C}$ at a pressure of 101 kPa it occupies a volume of $400 \mathrm{~cm}^{3}$ .

Deduce the molecular formula of the compound.

$\quad \mathrm{C}_{6} \mathrm{H}_{14}$ ;

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1.4.4—Empirical and molecular formulas question 1