Question

Complete combustion of a hydrocarbon gives 0.66 g of `CO_(2)` and 0.36g of `H_(2)O`. Find the empirical formula of the compound.

Answer 1

Let the mass of the substance taken = w g
`:. % C = (12)/(44) xx(0.66)/(w) xx 100 = (18)/(w)`
and `% H = (2)/(18) xx (0.36)/(w) xx 100 = (4)/(w)`
Ratio of atoms, `C : H = (18)/(w) xx (1)/(12) : (4)/(w) xx (1)/(1) = 3 : 8`
Hence, E.F. = `C_(3)H_(8)`.