Question

A compound contain 25% hydrogen and 75% carbon by mass. The empirical formula of the compound is:

• A. $C{H}_4$
• B. $C_2{H}_2$
• C. $C_2{H}_6$
• D. $C_2{H}_4$

Answer 1

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

$\begin{array}{ccccc}\text{Element}& \text{Atomic mass}& \%& \text{Relative no. of atoms}& \\ H& 1& 25& 25& \frac{25}{6.25}=4\\ C& 12& 75& \frac{75}{12}=6.25& \frac{6.25}{6.25}=1\end{array}$
So, the empirical formula is $C{H}_4$.