The answer is: volume of nitrogen is 70L.
Chemical reaction: N₂H₄ + O₂ → N₂ + 2H₂O.
m(N₂H₄) = 100 g; mass of hydrazine.
M(N₂H₄) = 32 g/mol; molar mass of hydrazine.
n(N₂H₄) = m(N₂H₄) ÷ M(N₂H₄).
n(N₂H₄) = 100 g ÷ 32 g/mol.
n(N₂H₄) = 3.125 mol; amount of hydrazine.
m(O₂) = 100 g; mass of oxygen.
M(O₂) = 32 g/mol; molar mass of oxygen.
n(O₂) = 100 g ÷ 32 g/mol.
n(O₂) = 3.125 mol; amount of oxygen.
From chemical reaction: n(O₂) : n(N₂) = 1 : 1; n(O₂) = n(N₂).
n(N₂) = 3.125 mol; amount og nitrogen gas.
V(N₂) = n(N₂) · Vm.
Vm = 22.4 L/mol; molar volume.
V(N₂) = 3.125 mol · 22.4 L/mol.
V(N₂) = 70 L.
There is not excess reagent, because hydrazine and oxygen are all used in chemical reaction.
