What is the percent composition of oxygen in MgXO3? X has a mass of 28.09 g/mol

Answer 1

Mg = 24.31 g/mol x 1 = 24.31 g

X = 28.09 g/mol x 1 = 28.09 g

O = 16 g/mol x 3 = 48 g

Total mass = 100.4 g

% O = 48 g / 100.4 g (x100%) = 47.81%