Correct option is C)
The molar mass of Ca(NO
3
)
2
=40.1+2×(14+3(16))=40.1+2×(62)=164.1g/mol.
1 mole (164.1 g) of calcium nitrate will contain 6 moles of O atoms.
The atomic mass of oxygen is 16 g/mol.
6 moles of oxygen atoms corresponds to 6×16=96g.
The percent of oxygen in calcium nitrate =
164.1
96×100
=58 %.
