What is the percent composition of Phosphorous in Ca₃(PO₄)₂?

Answer 1

Identify the question:

% of Phosphorous

Calculate total molar mass of Ca₃(PO₄)₂:

•Get molar mass from periodic table

Ca: 40.078 g/mol • 3 = 120.234

•multiply by the subscript

P: 30.974 g/mol • 2 = 61.948

•distribute the 2 inside the parenthesis

O: 15.999 g/mol • 8 = 127.992

•distribute the 2 inside the parenthesis

Total molar mass:

120.234 + 61.948 + 127.992 = 310.174 g/mol

(Mass of Phosphorous / Total Mass) • 100 = % Phosphorous

-(61.948 / 310.174) • 100 = 19.97%

Answer:

19.97% Phosphorous