In an aqueous solution, iron(III) ions react with iodide ions to give iron(II) ions and triiodide ions, I3-. Suppose the initial concentration of Fe3+ ions is 0.200 M, the initial I- ion concentration is 0.300 M, and the equilibrium concentration of I3- ions is 0.0866 M. What is the value of Kc? 2 Fe3+(aq) + 3 I-(aq) ⇄ 2 Fe2+(aq) + I3-(aq) Kc =

The value of the equilibrium constant is .

Explanation:

The initial concentration of ferric ions

The initial iodide ion concentration =

The equilibrium concentration of

Initially

0.200 M        0.300 M

At equilibrium:

(0.200M-2x)   (0.300-3x)           2x               x

The expression of equilibrium constant is given by :

Putting value of x :

x = 0.0866 M

The value of the equilibrium constant is .