What is the percent composition by mass for sodium (Na) in sodium phosphate (Na3PO4)? % Na = (______/______)x100% = _______% NNA

The percent composition by mass for sodium (Na) in Sodium phosphate (Na₃PO₄) : 42.07%
Given
Compound of Sodium phosphate (Na₃PO₄)
Required
The percent composition by mass for sodium (Na)
Solution
The Comparative Law (Proust ) : compounds are formed from elements with the same Mass Comparison
MW Na₃PO₄ = 163,94 g/mol
Ar Na=22,989769g/mol
[tex]\tt \%mass~Na=\dfrac{3.Ar~Na}{MW~Na_3PO_4}\times 100\%\\\\\%mass~Na=\dfrac{3\times 22.99}{163.94}\times 100\%\\\\\%mass~Na=42.07\%~Na[/tex]