2NaN3 (s) --> 3N2(g)+2Na(s) If an airbag fills with 3.75 mol of nitrogen gas, 1) How many moles of sodium azide are decomposed? 2) What is the mass of sodium produced?

Question

I need the answer to part one and part 2 of this question.

part one is: how many moles of sodium azide is decomposed?

part two is: what is the mass of sodium produced?

Answer 1

2NaN₃(s) <==> 3N₂(g) + 2Na(s) .. balanced equation for decomposition of sodium azide (NaN₃)

To answer part 1, we will use dimensional analysis and the stoichiometry of the balanced equation:

First, we must find the mols of N2 gas produced. Then work backwards to find moles of NaN₃ and then for part 2, convert moles of NaN₃ to grams of NaN₃

moles of N₂ gas: Since no information is given about temperature and pressure, we will assume STP

At STP 1 mole of N₂ = 22.4 L, therefore ... 3.75 L x 1 mol N₂ / 22.4 L = 0.167 moles N₂

Part 1) moles NaN₃ = 0.167 mols N₂ x 2 mol NaN₃ / 3 mols N₂ (see balanced equation)

moles NaN₃ = 0.112 moles

Part 2) grams NaN₃; molar mass NaN₃ = 65.0 g / mol

0.112 mols NaN₃ x 65.0 g / mol = 7.25 g NaN₃