Consider the reaction below:
A reaction vessel contains 27.5 g of N2H4 and 74.9g of N2O4.
I think the limiting reactant is N2. To balance the equation, one multiplies N by 2 . There are .8 moles according to my calculations. 2 X .8 = 1.6 grams. .8 moles/28gN2 X 7 = 2.45.