Question

Automobile air bags are inflated with nitrogen gas, which is formed by the decomposition of solid sodium azide (NaN3). The other product is sodium metal. Calculate the volume of nitrogen gas at 27 °C and 756 torr formed by the decomposition of 125 g of sodium azide.

Answer 1

Answer: 71.65 L

Step-by-step explanation:

Decomposition of sodium azide is shown by equation below:

`2NaN_3\rightarrow 2Na+3N_2`

`\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}`

`\text{Number of moles of sodium azide}=(125g)/(65g/mol)=1.92moles`

According to stoichiometry:

2 moles of
`NaN_3` produce 3 moles of
`N_2`

Thus 1.92 moles of
`NaN_3` will produce=
`(3)/(2)* 1.92=2.88` moles of
`N_2`

According to the ideal gas equation:

`PV=nRT`

P = Pressure of the gas = 756 torr = 0.99 atm (1 torr= 0.0013 atm)

V= Volume of the gas = ?

T= Temperature of the gas = 27°C = 300 K (0°C = 273 K)

R= Gas constant = 0.0821 atmL/K mol

n= moles of gas= 2.88

`V=(nRT)/(P)=(2.88* 0.0821* 300)/(0.99)=71.65L`

Thus the volume of nitrogen gas at 27 °C and 756 torr formed by the decomposition of 125 g of sodium azide is 71.65 L