Question

In older airbags, sodium azide, NaN3, was used as a source of nitrogen gas to rapidly inflate the airbag. This practice was mostly discontinued due to the high toxicity of sodium azide. The reaction of interest is 2 NaN3 (s) → 2 Na (s) + 3 N2 (g) 

How many grams of N2 are produced if a 35.0 g charge of NaN3 decomposes?

Considering the same prompt, suppose I wanted to inflate a 125 L airbag with N2 (g) to a density of 0.450 g N2 / L. This is more or less a typical value for the passenger airbag. To do so I would need Answer g of N2 (g).

Considering the reaction for the decomposition of sodium azide, this would require a Answer g of NaN3.

This same process would produce Answer g Na (s). Keep in mind that sodium metal is highly reactive, and that a dose of ~ 2 g of sodium azide can be lethal. Sodium azide is still used in some airbags, but it has largely been phased out due to the legitimate safety concerns. 

Answer 1

first convert 75.0 g to Moles by dividing by 28g/mol. = 2.68 moles N₂

Based on the balanced equation reactants to product ratio are 2:3 for Azide: Nitrogen gas. This means for every 3 moles of Nitrogen gas produces, 2 moles of Sodium Azide are needed.

This is a dimensional analysis question by using the fence method.

Start with moles calculated from above.

2.68 Moles N₂ *(2 moles NaN₃/3 moles N₂)=1.79mol NaN₃(65g/mol)= 116.35 g or with sig. figs 116g NaN₃