Question

A hydrocarbon has the following composition by mass: $C=90\%,H=10\%$. Thus, the empirical formula of hydrocarbon is:

• A. $C_3{H}_8$
• B. $C_2{H}_6$
• C. $C_3{H}_4$
• D. $C_3{H}_6$

Answer 1

The correct option is C $C_3{H}_4$

$C=\frac{90}{12}=7.5$

$H=\frac{10}{1}=10$

Simplest ratio: $C=\frac{7.5}{7.5}=1$

$H=\frac{10}{7.5}=\frac{4}{3}$

Whole number ratio: $C=3,H=4$

Therefore empirical formula is $C_3{H}_4$ .