A gaseous hydrocarbon contains 82.76% of carbon. Given that its vapour density is 29,find its molecular formula. [C = 12, H = 1]

Explanation

Empirical formula = `C_2H_5`
Empirical formula mass = `(12 xx 2) + (1 xx 5)` = 24 + 5 = 29
Vapour density `rarr` 29 (Given)
Molecular mass = `V.D. xx 2 = 29 xx 2` = 58 gm
Molecular formula mass = `n xx "Empirical formula mass"`
`implies n= ("Molecular Formula mass")/("Emprirical Formula mass") = (58)/(29)` = 2
Molecular formula = `n xx" Empirical formula" = 2 xx C_2H_5 = C_4H_(10)`