Sadie M. answered 04/22/19
Chemistry Teaching Expert! 8+ Years Experience- General & Organic Chem
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