Question

The empirical formula and molecular mass of a compound are $CH _{2} O$ and $150\, g / mol$ respectively. The molecular formula of the compound can be given as $C _{ x } H _{ y } O _{ x }$. The value of ' $x$ ' is________.

Answer 1

Given: Empirical formula $= CH _{2} O$
Empirical formula mass $=1 \times 12+2 \times 1+16 \times 1$
$=30\, g$
Molecular mass $=150\, g$
Molecular formula $= n \times$ empirical formula
$n =\frac{\text { Molecular mass }}{\text { Empirical formula mass }}=\frac{150}{30}=5$
$\therefore $ Substituting the value of $n$ in equation (i),
Molecular formula of
$C _{x} H _{y} O _{x}=5 \times$ empirical formula
$=5 \times CH _{2} O = C _{5} H _{10} O _{5}$
Hence, $x=5$