In an aqueous chloride solution cobalt(II) exists in equilibrium with the complex ion CoCl42-. Co2+(aq) is pink and CoCl42-(aq) is blue.

At Low Temperature the pink color predominates. At High Temperature the blue color is strong.

If we represent the equilibrium as:

COCl4^2-(aq) <--> CO2+(aq) + 4Cl-(aq)

We can conclude that:

1. This reaction is:

a. Exothermic

b. Endothermic

c. Neutral

d. More information is needed to answer this question.

2. When the temperature is decreased the equilibrium constant, K:

a. Increases

b. Decreases

c. Remains the same

d. More information is needed to answer this question.

3. When the temperature is decreased the equilibrium concentration of Co2+:

a. Increases

b. Decreases

c. Remains the same

d. More information is needed to answer this question.