Question

QUESTION 3 Automobile airbags use the decomposition of sodium azide, NaN3, to provide gas for rapid inflation 2 NaN3(s) - 2 Na(s) + 3 N2(9) Using stoichiometry and the ideal gas law, calculate the mass (ing) of NaN3 required to provide 42 L of N2(g) at 28.3 °C and 1.00 atm?

Answer 1

Given:

P = 1.0 atm

V = 42.0 L

T = 28.3 oC

= (28.3+273) K

= 301.3 K

find number of moles using:

P * V = n*R*T

1 atm * 42 L = n * 0.08206 atm.L/mol.K * 301.3 K

n = 1.70 mol

From reaction,

Mol of NaN3 required = (2/3)*mol of N2

= (2/3)*1.70 mol

= 1.13 mol

Molar mass of NaN3,

MM = 1*MM(Na) + 3*MM(N)

= 1*22.99 + 3*14.01

= 65.02 g/mol

use:

mass of NaN3,

m = number of mol * molar mass

= 1.13 mol * 65.02 g/mol

= 73.47 g

Answer: 73.5 g