Kc for the reaction of hydrogen and iodine to produce hydrogen iodide. H2(g) + I2(g) ⇌ 2HI(g)

is 54.3 at 430°C. Calculate the equilibrium concentrations of H2, I2, and HI at 430°C if the initial concentrations are [H2] = [I2] = 0 M, and [HI] = 0.391 M.

Explanation:

Hello.

In this case, for this equilibrium problem, we first realize that at the beginning there is just HI, it means that the reaction should be rewritten as follows:

Whereas the law of mass action (equilibrium expression) is:

That in terms of initial concentrations and reaction extent or change turns out:

And the solution via solver or quadratic equation is:

Whereas the correct answer is 0.183 M since the other value yield a negative concentration of HI at equilibrium (0.391-2*0.210=-0.029M).This, the equilibrium concentrations are:

Regards.

4d^55s^1 ( third choice)