Answer : The value of the equilibrium constant for this reaction is

Solution : Given,
Concentration of HCl at equilibrium = 0.80 M
Concentration of
at equilibrium = 0.20 M
Concentration of
at equilibrium = 3.0 M
Concentration of
at equilibrium = 3.0 M
Now we have to calculate the value of equilibrium constant.
The given equilibrium reaction is,

The expression of
will be,
![K_c=([Cl_2]^2[H_2O]^2)/([HCl]^4[O_2])](https://img.qammunity.org/2020/formulas/chemistry/middle-school/j9tik7ru4vxrc4rpphfswfuhxry2kjwzow.png)
Now put all the values in this expression, we get:


Therefore, the value of the equilibrium constant for this reaction is
