Question

Air-bags can be inflated by the decomposition of sodium azide, NaN3. At 25.0◦C and 1.10 atm, what volume of N2(g) is produced by the decomposition of 71.4 g NaN3 under the following chemical reaction: 2NaN3(s) → 2Na(l) + 3N2(g) Express your answer in liters. Please only enter the numerical value of your answer.

Answer 1

The reaction is

2NaN3(s) → 2Na(l) + 3N2(g)

The stoichiometry shows that 1 moles of NaN3 will give 3 moles of N2

Or we can say that 65 X 2 grams if NaN3 will give 3 moles of N2

So 1 gram will give = 3 / 130 moles

so 71.4 grams will give = 3 X 71.4 / 130 moles = 1.65 moles of N2

Now let us calculate the volume occuped by these moles of N2 at the given conditions

PV = nRT

n = 1.65

R = 0.0821 I(gas constant)

T = 25 C = 298 K

P = 1.1 atm

So Volume = 1.65 X 0.0821 X 298 / 1.1 = 36.69 Litres