Question

Calculate the mass percentage of potassium in K3PO4

Answer 1

1) determine molar mass of K₃PO₄

$=3(39.10)+30.97+4(16)\\=212.27\ g/mol$

2) determine total mass of potassium atoms in K₃PO₄

$=3(39.10)\\=117.3\ g$

4) divide by molar mass and multiply by 100

$=\frac{117.30}{212.27}$ × $100$

= 55.25981062% (round as you wish)