Answer to Question #105838 in Inorganic Chemistry for Jane

Question

20.0g NH3 and 50.0g O2 are allowed to react which is the limiting reagent?

Answer 1

$4NH_3(g) +3 O_2(g) \longrightarrow 2N_2(g)+6H_2O(g)$

molar mass of NH₃= 14+3=17 $\frac{g}{mole}$ , given mass ammonia=20 g

$moles of NH_3= \frac{given mass}{molar mass}=\frac{20}{17}=1.18 mole$

molar mass of O₂=32 g/mole

$mole of O_2= \frac{given mass}{molar mass}= \frac{50}{32}=1.56 mole$

from the above reaction it is clear that

4 mole of ammonia react with 3 mole of oxygen

so, 1 mole of ammonia will react with $=\frac{3}{4} mole of O_2= 0.75 mole$ of O₂

so 1.18 mole of NH₃ will react with $1.18\times.75=0.885$ mole of O₂

so from above situation NH₃ is limiting reagent