Question

110 g of manganese was extracted from 174 g of manganese oxide. (Ar: Mn=55, O=16)

a) What mass of oxygen atoms is this?

Answer 1

Molar mass of MnO$_2=87g/mol$

Moles in 174g of MnO$_2=2$

Mass of Oxygen in 174g of MnO$_2=32×2=64g$