Sodium azide decomposes rapidly to produce nitrogen gas. 2 NaN₃(s) → 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 °C? (R = 0.08206 L⋅atm/mol⋅K)

Question

Quizplus · Accepted Answer

Using the ideal gas law, PV = nRT, calculate moles of N2 needed: n = (1.50 atm)(60.0 L) / (0.08206 L⋅atm/mol⋅K)(305 K) = 3.59 mol N2. From the reaction, 2 mol NaN3 produces 3 mol N2, so 3.59 mol N2 requires 2.39 mol NaN3. Molar mass of NaN3 is 65.01 g/mol, so mass = 2.39 mol × 65.01 g/mol = 155.4 g, approximately 156 g.

Sodium Azide Decomposes Rapidly to Produce Nitrogen Gas