Question

Calculate the volume occupied by 35g of $N_2{O}_4$ when partially dissociated at 308K and 1 atm pressure, the degree of dissociation at the temperature being $27\%$.

Answer 1

At normal temperature and pressure (20 celsius and 1 atm), the volume occupied by 1 mole of gas by ideal gas law is 22.4 litres.
Molecular wt of $N_2{O}_4=2\times 14+4\times 16=92g/mol$
Therefore, no. of moles of $N_2{O}_4=\frac{35}{92}=0.37$
Therefore, volume of this ammount $N_2{O}_4$ at NTP= 22.4 litres $\times$ 0.37 = 8.34 litres

Now according to ideal gas law,
$\frac{V_1}{V_2}=\frac{T_1}{T_2}$
therefore, at 308 Kelvin,
$V2=\frac{308}{293}\times 8.34litres=8.77Litres$
This will the volume occupies by $N_2{O}_4$ at the given conditions.