Sodium azide decomposes rapidly to produce nitrogen gas.2 NaN₃(s) $\to$ 2 Na(s) + 3 N₂(g)
What mass of sodium azide will inflate a 60.0 L airbag for a car to a pressure of 1.50 atm at 32 ^$\circ$C? (R = 0.08206 L.atm/mol.K)

Question

Sodium azide decomposes rapidly to produce nitrogen gas.2 NaN₃(s)

\to

2 Na(s) + 3 N₂(g)
What mass of sodium azide will inflate a 60.0 L airbag for a car to a pressure of 1.50 atm at 32 ^$\circ$C? (R = 0.08206 L.atm/mol.K)

Quizplus · Accepted Answer

The first step is to use the ideal gas law to calculate the number of moles of nitrogen gas needed to inflate the airbag:

PV = nRT

n = PV/RT = (1.50 atm)(60.0 L)/(0.08206 L⋅atm/mol⋅K)(305 K) = 3.09 mol

Since the balanced equation shows that 2 moles of sodium azide produce 3 moles of nitrogen gas, we can use stoichiometry to calculate the mass of sodium azide needed:

2 mol NaN3 = 3 mol N2
x mol NaN3 = 3.09 mol N2
x = (3.09 mol N2)(2 mol NaN3/3 mol N2) = 2.06 mol NaN3

Finally, we can calculate the mass of sodium azide using its molar mass:

m = nM = (2.06 mol)(65.01 g/mol) = 134 g

The closest answer choice is C) 156 g.

Sodium Azide Decomposes Rapidly to Produce Nitrogen Gas →\to→ 2 Na(s)+ 3 N2(g) What Mass of Sodium Azide Will

Sodium Azide Decomposes Rapidly to Produce Nitrogen Gas $\to$ 2 Na(s)+ 3 N₂(g)
What Mass of Sodium Azide Will