Question

Formulate the expression for Kc for the alternate reaction justcited.
b. Find Kc as you did in Problem 1; take due account of the factthat two moles SCN- are used up per mole Fe(SCN)2+ formed.

Step 1. Results are as in Problem 1.
Step 2. How many moles of Fe(SCN)2+ are in the mixture atequilibrium? (You should use Eq. 3.)

_________moles Fe(SCN)2+

How many moles of Fe3+ and SCN- are used up in making theFe(SCN)2+?
.
_________ moles Fe3+; _________moles SCN-

Step 3. How many moles of Fe3+ and SCN-remain in solution atequilibrium? Use the results of Steps 1 and 2, noting that no.moles SCN- at equilibrium = original no. moles SCN- -(2 X no. molesFe(SCN)2+).

.

. _________moles Fe3*; _________moles SCN'

Step 4. What are the concentrations of Fe3+, SCN-, and Fe(SCN)2+ atequilibrium? (Use Eq. 3 and the results of Step 3.)
[Fe3+]= _________M; [SCN-] = _________M; [Fe(SCN)2+]=_________M

Step 5. Calculate Kc on the basis that the alternate reactionoccurs. (Use the answer to Part 2a.)
Kc=_________