Question

How many moles of magnesium lhosphate will contain 0.2 mkles of oxygen?

Answer 1

1 mole of magnesium phosphate contains 8 moles of oxygen atoms ( as can be seen from chemical formula of magnesium phosphate there are 8 atoms of oxygen in one molecule of magnesium phosphate) . So, 1 mole contains 8 mole atoms, Implies, 0.25 moles contain 0.25*8 = 2 mole atoms of oxygen.