Question

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2nan3(s) → 2na(s) + 3n2(g) how many grams of sodium azide are required to produce 33.0 g of nitrogen?

Answer 1

Answer is: 51.047 grams of sodium azide are required.

Balanced chemical reaction: 2NaN₃(s) → 2Na(s) + 3N₂(g).
m(N₂) = 33.0 g; mass of nitrogen,
M(N₂) = 28 g/mol; molar mass of nitrogen.
n(N₂) = 33 g ÷ 28 g/mol.
n(N₂) = 1.178 mol; amount of substance.
From chemical reaction: n(N₂) : n(NaN₃) = 3 : 2.
n(NaN₃) = 2 · 1.178 mol ÷ 3.
n(NaN₃) = 0.785 mol.
M(NaN₃) = 65 g/mol.
m(NaN₃) = n(NaN₃) · M(NaN₃).
m(NaN₃) = 0.785 mol · 65 g/mol.
m(NaN₃) = 51.047 g.