# What is the percent composition of K_3PO_4?

May 22, 2016

%K = 55.26%
%P = 14.59%
%O = 30.15%

#### Explanation:

Percentage composition of a particular molecule is usually in regard to one element within the molecule.

To work out the percentage composition of a particular molecule, we look at the percentage of the whole weight of the molecule that the specific element takes up.

The working:
Atomic mass:
$K$ = $39.10$
$P$ = $30.97$
$O$ = $16.00$
Molecular mass of ${K}_{3} P {O}_{4}$ = $\left(39.10 \times 3\right) + 30.97 + \left(16.00 \times 4\right)$ = $212.27$

%K = [(3xx39.10)/212.27]xx100=55.26%
%P = (30.97/212.27)xx100=14.59%
%O = [(4xx16.00)/212.27]xx100=30.15%