# Example 2 - Empirical Formula

From an experiment, a scientist found that a hydrocarbon contains 85.7% of carbon according to its mass. Find the empirical formula of the hydrocarbon. [Relative atomic mass: Carbon = 12; Hydrogen = 1]

 Element C H Percentage $85.7%$ $14.3%$ Mass in 100g $85.7g$ $14.3g$ Number of mole $85.7 12 =7.142mol$ $14.3 1 =14.3mol$ Simple ratio $7.142 7.142 =1$ $14.3 7.142 =2$