Question.
Calculate the mass percent of different elements present in sodium sulphate $\left(\mathrm{Na}_{2} \mathrm{SO}_{4}\right)$.
Calculate the mass percent of different elements present in sodium sulphate $\left(\mathrm{Na}_{2} \mathrm{SO}_{4}\right)$.
Solution:
The molecular formula of sodium sulphate is $\mathrm{Na}_{2} \mathrm{SO}_{4}$.
Molar mass of $\mathrm{Na}_{2} \mathrm{SO}_{4}=[(2 \times 23.0)+(32.066)+4(16.00)]$
$=142.066 \mathrm{~g}$
Mass percent of an element $=\frac{\text { Mass of that element in the compound }}{\text { Molar mass of the compound }} \times 100$
Mass percent of sodium
Mass percent of sulphur
Mass percent of oxygen
The molecular formula of sodium sulphate is $\mathrm{Na}_{2} \mathrm{SO}_{4}$.
Molar mass of $\mathrm{Na}_{2} \mathrm{SO}_{4}=[(2 \times 23.0)+(32.066)+4(16.00)]$
$=142.066 \mathrm{~g}$
Mass percent of an element $=\frac{\text { Mass of that element in the compound }}{\text { Molar mass of the compound }} \times 100$
Mass percent of sodium
Mass percent of sulphur
Mass percent of oxygen