Question

The equilibrium constant for the decomposition of PCl5 at 250 celcius is 1.05. PCl5(g)-->PCl3(g)+Cl2(g) If the equilibrium pressures of PCl5 and PCl3 are .875 atm and .463 atm, respectively, then what is the equilibrium partial pressure of Cl2 at 250 celsius.

Answer 1

Answer : The equilibrium partial pressure of Cl₂ at 25°C is, 1.98 atm

Explanation :

For the given chemical reaction:

`PCl_5(g)\rightleftharpoons PCl_3(g)+Cl_2(g)`

The expression of
`K_p` for above reaction follows:

`K_p=(P_(PCl_3)* P_(Cl_2))/(P_(PCl_5))`

We are given:

`P_(PCl_5)=0.875atm`

`P_(PCl_3)=0.463atm`

`K_p=1.05`

Putting values in above equation, we get:

`1.05=(0.463* P_(Cl_2))/(0.875)\\\\P_(Cl_2)=1.98atm`

Thus, the equilibrium partial pressure of Cl₂ at 25°C is, 1.98 atm