Question

The chemical reaction for the generation of gas in an automobile safety air bag is 2NaN3(s) → 2Na(s) + 3N2(g) What volume of gas is produced if there are 130.0 grams of NaN3 used in the reaction? (The density of nitrogen gas is 0.916 g/L.) Please show your work.

Answer 1

Molar mass of NaN3,

MM = 1*MM(Na) + 3*MM(N)

= 1*22.99 + 3*14.01

= 65.02 g/mol

mass of NaN3 = 1.3*10^2 g

mol of NaN3 = (mass)/(molar mass)

= 1.3*10^2/65.02

= 2.0 mol

Balanced chemical equation is:

2NaN3(s) ---> 2Na(s) + 3N2(g)

According to balanced equation

mol of N2 formed = (3/2)* moles of NaN3

= (3/2)*2.0

= 3.0 mol

Molar mass of N2 = 28.02 g/mol

mass of N2 = number of mol * molar mass

= 3.0*28.02

= 84.0 g

Now use:

density = mass / volume

0.916 g/L = 84.0 g / volume

volume = 91.7 g

Answer: 91.7 g