Question

Number of hydrogen atoms per molecule of a hydrocarbon A having $858 \%$ carbon is_____ (Given: Molar mass of $A =84 g mol ^{-1}$ )

Answer 1

The correct answer is 12.

Element	Percentage	Mole	Mole ratio
C	85.8	$\frac{85.8}{12}=7.5$	1
H	14.2	$\frac{14.2}{1}=14.2$	2
Empirical formula (CH2​)
14×n=84
n=6
∴ Molecular formula C6​H12​