Question

Cobalt ions form complex ions with water and chloride as shown in the reaction. The left side of the reaction is pink, and the right side of the reaction is blue.
Co(H₂O) ₆ ² ⁺ + 4CI ⁻ + heat ⇌ CoCI ₄ ² ⁻ + 6H ₂O

Which statement about the system at equilibrium is correct?
1. Cooling a purple solution will turn it pink
2. Heating a blue solution will turn it purple
3. Adding water to a purple solution will turn it blue
4. Adding hydrogen chloride (HCI) to a blue solution will turn it purple

Answer 1

Remember Le Chatelier's Principle. If we do something to a chemical system at equilibrium the system will try to undo what we did. Lets look at them 1 by 1.
4. Adding HCl will shift the equilibrium to the right (to get rid of the Cl^- that has been added). So statement 5 is not right.
3. Adding water will shift the equilibrium to the left (to get rid of the H2O that was added). So statement 3 is not right.
Analyze statements 1 and 2 the same way. Post your work if you want me to check it.

Answer 2

Would it be #2? Wouldn’t heating the blue solution cause it to go towards pink and make it purple?

Answer 3

Wait it would be 1, the purple would turn pink when cooled down