Question

I2 + Cl2 →2ICl Kp=81.9. A reaction mixture initially P(I2)=P(Cl2)=P(ICl)= 0.1 atm. How to determine the direction of the reaction will proceed?

Answer 1

The equilibrium will shift to the right.

Explanation:

The equilibrium in question is the following:

`I_2+Cl_2rightleftharpoons2ICl" " " "K_P=81.9`

The expression of `K_P` is: `K_P=(P_(ICl)^2)/(P_(I_2)*P_(Cl_2)`

Since we have the initial pressures, we will determine the direction of the equilibrium from the reaction quotient `Q_P`.

The expression of `Q_P` is: `Q_P=((P_0)_(ICl)^2)/((P_0)_(I_2)*(P_0)_(Cl_2))`

`=>Q_P=(0.1)^2/((0.1)xx(0.1))=1 < K_P`

Since `Q_P < K_P` then the equilibrium will shift to the right to increase the pressure of the product (numerator) and decrease the pressure of reactants (denominator).