try to use the relation between vapour density and degree of dissociation...
if u still wont get tell me.
At 200*C PCl5 dissociates as follows:
PCl5(g) + PCl3(g) +Cl2(g)
It was found that the equilibrium vapours are 62 times as heavy as hydrogen.Find the degree of dissociation of PCl5 at 200*C..
??
try to use the relation between vapour density and degree of dissociation...
if u still wont get tell me.