When 2.50 mol of mg3n2 are allowed to react how many moles of h2o also react?

Notice that in the equation given, there is 1 mol of Mg3N2 and 6 mol of H2O. Consequently, the question is requesting, if we took 2.5 mol of Mg3N2, how many mol of H2O would be essential to complete a similar reaction -- in quintessence, multiplying everything by 2.5: 

the solution would be: 6 * 2.5 = 15 mol

28.144 g of , then the balanced chemical reaction is:

It is given that is present in excess, so it is an excess reagent and Al is the limiting reagent.

Now, 2 moles of Al produces 1 mole of , which means that (2×27g) = 54g of Al produces 102g of .

Therefore, 14.9g of Al will produce =

                                                          = 28.144g of