Kc= Equilibrium cosntant = 0.041 at 250 deg.c
for PCl5----> PCl3+Cl2 , Kc =[Cl2] [PCl3]/ [PCl5] =0.041
                      Â
PCl5Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
 Â
PCl3Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
Cl2
Initilal             Â
0.135/2.15
=0.063Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
0Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
0
let x= change of PCl5 due to equilibium
Equilibrium
0.063-x                                Â
x                             Â
x
Kc= x2/(0.063-x)= 0.041
this equaiion can be solved using solver of excel by asssuming
some initial value of x=0.0343
PCl5= 0.063-0.0343= 0.0287Â Â Â PCl3= 0.0343 and
Cl2= 0.0343
