Initially the concentration of H2 is 2.0M , I2 is 2.0M and HI is 8.0M. The vessel is heated up to 675 degrees at equilibrium the concentration of HI changes to become 6.0M. Calculate the value of k at this temperature.

The value of K at this temperature = 2.25

Explanation:

According to question the equilibrium reaction is

                                           H₂(g) + I₂(g) ⇄ 2 HI(g)

       Initial concentration   2           2             8

         At equilibrium     2 + 2x     2 + 2x          8 - 2x

At equilibrium concentration of HI changes to become 6 Molar

                      So 8 - 2x = 6

                      or, x = 1

So concentration of H₂ = 2 + 2 x 1 = 4 molar

concentration of I₂ = 2 + 2 x 1 = 4 molar

                  Kc =

     ⇒          Kc =

     ⇒         Kc = = 2.25