Question

Sodium azide, NaN3, is the primary gas-forming compound present in many car airbag systems. It is synthesized by reacting sodium amide, NaNH2, with the gas nitrous oxide, N2O, according to the following equation. 2 NaNH2 + N2O → NaN3 + NaOH + NH3 A sample of sodium azide is prepared by reacting 21.23 g NaNH2 with 11.63 g N2O. (a) What is the limiting reagent? (b) How much sodium azide is produced?

Answer 1

2 NaNH2 + N2O --------------------> NaN3 + NaOH + NH3

78g 44g 65g 40g 17g

21.23g 11.63g

78 g NaNH2 needs ------------------> 44 g N2O

21.33 g NaNH2 needs -------------> 44 x 21.33 / 78 = 12.03 g N2O

but we have only 11.63 g . so total N2O is consumed . it is limiting reagent

limiting reagent = N2O

the product is based on limiting reagent

44 g N2O gives ------------------> 65 g NaN3

11.63 g N2O gives -------------> 65 x 11.63 / 44 = 17.18 g

sodium azide formed = 17.18 g