The vapour density of N₂O₄ at certain temperature is 30. What is the percentage dissociation of N₂O₄ at that temperature? 

 

Degree of decomposition,

D = V.D of undissociated species

d = V.D of equilibrium mixture (observed vapour density)

${\mathrm{N}}_2{\mathrm{O}}_4\left(\mathrm{g}\right) \rightleftharpoons 2{\mathrm{NO}}_2\left(\mathrm{g}\right)$;  n = 2 ;D = 46 ;d = 30

 $\mathrm{\alpha } =\frac{46-30}{30\left(2-1\right)}$ _; $\mathrm{\alpha } =\frac{16}{30}$; $\mathrm{\alpha } =0.5333$

Percentage dissociation of N₂O₄ = (0.5333 x 100)= 53.33%