Question: how many moles of magnesium phosphate will contain 0.25 moles of oxygen atom?
Answer: Magnesium phosphate Mg3(PO4)2. ==> 1mole of Mg3(PO4)2 contains 8 moles of oxygen atom. ==>? moles of Mg3(PO4)2 contains 0.25 moles of oxygen atom.