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.