An organic compound was analyzed and found to contain exactly $85.7\%$ carbon and $14.3\%$ hydrogen

Question

An organic compound was analyzed and found to contain exactly $85.7\%$ carbon and $14.3\%$ hydrogen by mass. The correct empirical formula for this compound is (Atomic weights: C=12, H=1)

Professor PC Thomas Classes · Answer

(b) : Given the percentages are C = 85.7% and H = 14.3%. The relative number of moles of Carbon = $\frac{85.7}{12} \approx 7.14$. The relative number of moles of Hydrogen = $\frac{14.3}{1} = 14.3$. The simplest molar ratio of C to H is $7.14 : 14.3$, which simplifies exactly to $1 : 2$. Therefore, the empirical formula of the compound is $\mathrm{CH}_2$.