Question

A gaseous hydrocarbon with empirical formula `CH_(2)` has a density of 12.5 g `gL^(-1)` at N.T.P The molecular formula of the compound is
A. `C_2H_2`
B. `C_6H_6`
C. `C_2H_4`
D. `C_3H_6`

Answer 1

Correct Answer - C
22.4 L of a gas/ vapour at N.T.P has a mass of 1.25 g .
22.4 L of the gas at NTP has a mass of
`=1.25 xx 22.4 g = 28 g `
`therefore` Mol mass of hydrocarbon =28
`there " Hydrocarbon " =C_2H_4`