Question

A compound has $C =40 \%, H =13.33 \%$ and $N =46.67 \% .$ The empirical formula is:

• A. $ CH_{4}N $
• B. $ C_{2}H_{5}N $
• C. $ CH_{2}N $
• D. $ CH_{4}N_{2} $

Answer 1

Answer: (A)

Consider the compound to be made of $100 g$. Convert percentile to weight in grams. then, convert wt. in grams to moles.
Moles of $C=40 / 12=3.33$
Moles of $H =13.33 / 1=13.33$
Moles of $N =46.6 / 14=3.33$
Now divide each mole value by lowest value of $n$ as:
$
\begin{array}{l}
C =3.33 / 3.33=1 \\
H =13.33 / 3.33=4.00 \\
N =3.33 / 3.33=1
\end{array}
$
The emperical formula is $CH _{4} N$.