A hydrocarbon contains 79.89% carbon and the remainder hydrogen. Determine the empirical formula of the compound.

Question

Quizplus · Accepted Answer

To find the empirical formula, calculate the moles of carbon and hydrogen based on their percentages and atomic masses. With 79.89% carbon, assuming 100g of the compound, there are 79.89g of carbon, which is 79.89g / 12.01g/mol = 6.65 mol of carbon. The remainder is hydrogen: 100g - 79.89g = 20.11g of hydrogen, which is 20.11g / 1.008g/mol = 19.95 mol of hydrogen. The ratio of carbon to hydrogen is approximately 1:3, making the empirical formula CH3.

A Hydrocarbon Contains 79