Automotive air bags inflate when a sample of sodium azide, , is very rapidly decomposed. What mass of sodium azide is required to produce 2.6 ft (73.6 L) of nitrogen gas with a density of 1.25 g/L?

sodium azide required = 142.4 g

Explanation:

Decomposition of sodium azide .

2NaN₃     =   2Na   +    3 N₂

2 mole                          3 mole of nitrogen

2 moles of sodium azide gives 3 moles of nitrogen

mol weight of sodium azide = 65

mol weight of nitrogen = 28

2 x 65 g of sodium azide gives 3 x 28 g of nitrogen .

130 g of sodium azide gives 84  g of nitrogen .

mass of nitrogen required = 1.25 x 73.6

= 92 g

84  g of nitrogen  requires decomposition of 130 g of  sodium azide

92 g of nitrogen  requires decomposition of 130x 92 / 84  g of  sodium azide

sodium azide required = 130x 92 / 84 = 142.4 g

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)