Respuesta :

the molecular formula of calcium oxide - CaO

The molar mass of CaO - 40 + 16 = 56 g/mol 

Which means that 1 mol weighs 56 g

Therefore 56 g of CaO is - 1 mol

Then 89.23 g is equivalent to - 1/56 x 89.23 = 1.6 mol of CaO.