Question

Consider the reaction below. At 500 K, the reaction is at equilibrium with the following concentrations. [PCI5]= 0.0095 M [PCI3] = 0.020 [CI2] = 0.020 M What is the equilibrium constant for the given reaction?

Answer 1

Answer: The equilibrium constant for the given reaction is 0.0421.

Step-by-step explanation:

`PCl_5\rightleftharpoons PCl_3+Cl_2`

Concentration of
`[PCl_5]` = 0.0095 M

Concentration of
`[PCl_3]` = 0.020 M

Concentration of
`[Cl_2]` = 0.020 M

The expression of the equilibrium constant is given as:

`K_c=([PCl_3][Cl_2])/([PCl_5])=(0.020 M* 0.020 M)/(0.0095 M)`

`K_c=0.0421` (An equilibrium constant is an unit less constant)

The equilibrium constant for the given reaction is 0.0421.

Answer 2

Answer: 0.042

Explanation:- Equilibrium constant is the ratio of concentration of products to the concentration of reactants each term raised to their stochiometric coefficients.

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

`K_c=([PCl_3][Cl_2])/([PCl_5])`

Given :
`[PCl_5]`= 0.0095 M

`[PCl_3]` = 0.020 M

`[Cl_2]` = 0.020 M

Putting the given values n the equation:

`K_c=([0.020][0.020])/([0.0095])=0.042`