Refer to the net ionic equation below to answer the following questions:

Question

Co(H2O)6^+2 + 4Cl- <==> CoCl^-2 + 6H2O

1. In what direction was the equilibrium shifted by:
a. Addition of HCl
b. Addition of water
c. Addition of AgNO3
d. Increasing the temperature
e. Decreasing the temperature

2. How do you explain the results described in answers 1a and 1b?

3. Explain the results observed when AgNO3 was added. (Hint: The concentration of something was being lowed.)

4. Is the reaction shown above exothermic or endothermic? How do you know?

Answer 1

Net Ionic Equation is:

Co(H2O)6^2+ +4Cl- <--> CoCl4^2- + 6H2O

Answer 2

1. In what direction was the equilibrium shifted by:
a. Addition of HCl
b. Addition of water
c. Addition of AgNO3
d. Increasing the temperature
e. Decreasing the temperature

Le Chatelier's Principle tells us that when a system at equilibrium is disturbed that it will shift to undo what we've done to it. Therefore,
a. Adding HCl it will shift to the right BECAUSE the reaction wants to use the extra HCl.
b. Now you do this one based on a.
c. Notice that AgNO3(aq) + Cl^-(aq) ==> AgCl(s) + NO3^-(aq). This REMOVES Cl^- from the rxn; therefore, it will shift (left/right) to undo what we've done.
d and e. I don't know the answers to these since you don't have the information about the rxn being endothermic or exothermic.

The answers to the other questions are included in the explanations above.

Answer 3

Thanks! I got the other answers.