The masses of carbon, hydrogen and oxygen in an organic compound are in the ratio 6: 1: 8 respectively. Which of the following pairs of formulae correspond to the above information? (Kerala CEE 2009) (a) CH O and CH CHO (b) CH O and C H O (c) C H O and C H O (d) C H O and HCHO (e) C H O and C H O Ans. (d) Sol. Element Relative Atomic / x y Simple ratio mass (x) mass (x) C 6 12 0.5 12 0.5 0.5 H 1 1 1 0.5 O 8 16 0.5 16 0.5 0.5 Hence, the empirical formula of the compound must be CH O . The formula of other compounds having CH O empirical formula are CH O or C H O , CH O or C H O and so on.