Question

Hydrazine (N2H4) and dinitrogen tetroxide (N2O4) react to form nitrogen gas and water vapor. Determine the limiting reactant and the mass of nitrogen produced by the reaction of 105.0 grams of dinitrogen tetroxide and 95.0 grams of hydrazine.

Answer 1

2N2H4 + N2O4   ---> 3N2 + 4H2O   isbalanced reaction

N2O4 moles = mass of N2O4 / Molar mass of N2O4

          = ( 105g) / ( 92g/mol) = 1.14 mol

N2H4 mol = ( mass of N2H4) / Molar mass of N2H4

            = 95g / ( 32g/mol) = 2.97 mol

as per reaction N2O4 mol needed = ( 1/2) N2H4 moles = ( 1/2)(2.97) = 1.4844 mol

N2O4 moles actually present = 1.14 mol which is less than required . Hence N2O4 is limiting reagent

N2 moles produced = 3 times of N2O4 moles = 3(1.14) = 3.42 mol

N2 mass = moles of N2 x molar mass of N2 = 3.42 mol x 28g/mol

= 95.8 g