Question

Calculate the mass percent composition of O in each compound.

calcium nitrate

Iron(II) sulfate

Carbon dioxide

Answer 1

Calcium Nitrate

Ca(NO3)2

Molar mass of compound = 40 + (14 + 16 * 3)2

=> 40 + 124

=> 164 gm/mol

Mass of Oxygen in Ca(NO3)2 = 16*3*2 = 96 gm/mol

Mass Percentage of O = 96/164 * 100 = 58.53%

FeSO4 ( Iron(II) Sulfate )

Maolar mass of FeSO4 = 55.85 + 32 + 16 * 4 = 151.85 gm/mol

Molar mass of Oxygen in FeSO4 = 4 * 16 = 64 gms

Mass Percentage of O = 64/151.85 * 100 = 42.14%

CO2( Carbon Dioxide )

Maolar mass of CO2= 12+ 16 * 2 = 44 gm/mol

Molar mass of Oxygen in CO2 = 2 * 16 = 32 gms

Mass Percentage of O = 32/44 * 100 =72.72%