E-14
Report: Experiment E - Le CHÂTELIER'S PRINCIPLE and INTERACTIVE
CHEMICAL EQUILIBRIA
Name
Section
Date
Laboratory Instructor
Part I: The Iron(III) Thiocyanate Equilibrium
1.
When Fe(NO3)
3(aq)
and KNCS
(aq)
were initially mixed they reacted and established an equilibrium with
[Fe(NCS)]
2+
(aq)
. Write the equilibrium constant expression for this reaction. Explain how each of the
concentrations and the value of the reaction quotient, Q, change from the time when the solutions were
mixed (i.e. time = 0), to when equilibrium was established. (K
eq
= 1.0 x 10³)
For the following questions, use Le Châtelier's Principle and the fill in the blank format given on the
Experiment E website to explain the effect of the reagent added on the [Fe(NCS)]
2+
(aq)
. equilibrium. Also,
support your answer with the appropriate balanced net ionic interactive equilibria.
2.
How does the addition of Fe(NO3)
3(aq)
affect the equilibrium position for reaction (8)? Explain.