Automobile airbags contain solid sodium azide, NaN 3 , that reacts to produce nitrogen gas when heated, thus inflating the bag. 2 NaN 3 ( s ) ⟶ 2 Na ( s ) + 3 N 2 ( g ) Calculate the value of work, w , for the system if 10.3 g NaN 3 reacts completely at 1.00 atm and 22 ∘ C.

Answer : The value of work done for the system is 581.462 J

Explanation :

First we have to calculate the moles of

Molar mass of = 65.01 g/mole

Now we have to calculate the moles of nitrogen gas.

The balanced chemical reaction is,

From the balanced reaction we conclude that

As, 2 mole of react to give 3 mole of

So, 0.158 moles of react to give moles of

Now we have to calculate the volume of nitrogen gas.

Using ideal gas equation:

where,

P = Pressure of gas = 1.00 atm

V = Volume of gas = ?

n = number of moles  = 0.237 mole

R = Gas constant =

T = Temperature of gas =

Putting values in above equation, we get:

As initially no nitrogen was present. So,

Volume expanded = Volume of nitrogen evolved

Thus,

Expansion work = Pressure × Volume

Expansion work = 1.00 atm × 5.74 L

Expansion work = 5.74 L.atm

Conversion used : (1 L.atm = 101.3 J)

Expansion work = 5.74  × 101.3 = 581.462 J

Therefore, the value of work done for the system is 581.462 J

there is none because earth is stationary and flat.