The number of ammonia in liters produced is calculated as follows
write the reacting equation
4NO2 +6H2O = 4NH3 + 7 O
H2O is the limiting reactant since 3 moles of H20 reacted completely with 3 x4/6 = 2 moles of NO2
At STP 1 mole = 22.4 L what about 2 moles
= 2 / 1 x22.4 =44.8 liters of ammonia