CH 202 Problem 3.63

3.63 Automotive airbags inflate when sodium azide, NaN₃, rapidly decomposes into its component elements:

2NaN₃(s) ----> 2Na(s) + 3N₂(g)

(a) How many mol of N₂ are produced by the decomposition of 1.50 mol NaN₃?

from the coefficient of NaN₃ and N₂ in the balanced equation,

so 2.25 mol N₂ is produced.

(b) How many grams of sodium azide are required to form 10.0 g of nitrogen gas?

here, we convert 10.0 g nitrogen ---> mol nitrogen ---> mol sodium azide ---> g sodium azide:

molar mass nitrogen:

molar mass sodium azide:

now,

(c) How many grams of sodium azide are required to produce 10.0 ft³ of nitrogen gas if the gas has a density of 1.25 g/L?

here, we have a volume and a density for nitrogen gas; we can find the mass of nitrogen gas, and then convert this mass to g sodium azide.

first, we have some units to deal with. lets convert cubic feet to liters first ( 1 in = 2.54 cm)

(3 sig figs)

so the mass of nitrogen corresponding to a volume of 10 ft³ is

so we convert 354 g nitrogen to g sodium azide:

DAC 7/2/08