(પરમાણ્વીય દળ $Ag =108\,u, Br =80\,u )$.
$0.5\, g \quad 0.4\, g$
$mol$ of $Br = mol$ of $AgBr =\frac{0.4}{188}$
$\%\, Br =\%\, Br =\frac{\frac{0.4}{188} \times 80}{0.5} \times 100$
$=34.04\, \%$
(પરમાણ્વીય દળ :- $Ag =108, Br =80\, g\, mol ^{-1}$ )