PCl5Â Â <--------------------------> PCl3 +
Cl2
7.95Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
0Â Â Â Â Â Â Â Â Â
0Â Â Â Â Â ----------------------> initial
pressure
-x                                         Â
+x      +x   Â
-----------------------> changed pressure
7.95 -
x                                    Â
x       x  Â
------------------------> equilibrium pressure
from data equilibrium pressure of Cl2 is given . that means x is
given
x= 3 atm
now equilibirum pressure of all components
PCl5 partial pressure = 7.95 -x = 7.95 -3 = 4.95 atm
PCl3 partial pressure  = x = 3 atm
Cl2 partial pressure  = x = 3 atm
now equilibrium
constant Kp
Kp = PPCl3 x PCl2 / PPCl5
Kp = 3 x 3 / 4.95
Kp = 1.82
-----------------------------(answer)
