posted by Hannah .
1) what mass of oxygen will react with 2.64g of magnesium?
2Mg + O2 -> MgO
I was going to do 2.64g * (1/2) from the equation but im not sure. Do I have to add a 2 in front of the MgO?
2) How many moles of sodium ions are present in 2.50 L of 0.300 M Na3PO4?
I know M=moles/L so .300= x/2.50 but the answer is 2.25 and i did not get that.