Question

The following equilibrium is formed when copper and bromide ions are placed in a solution:

heat + Cu(H2O)6 ^+2 (blue) + 4Br- <--> 6H2O + CuBr4^-2 (green)
A) answer the following questions when KBr is added to the solution:
1. What will happen to the equilibrium?
2. What will be the color of the solution?
3. Will the solution be hotter or cooler? Explain.
B) What will be the color of the solution when the solution is heated?

Answer 1

When KBr is added to the solution, the equilibrium will shift to the left, resulting in a more green color of the solution and a cooler temperature.

Step-by-step explanation:

1. When KBr is added to the solution, the equilibrium will shift to the left. This is because the addition of KBr introduces more Br- ions, which increases the concentration of the common ion in the equilibrium. According to Le Chatelier's Principle, the system will respond by shifting the equilibrium position to counteract the increase in Br- concentration. As a result, the formation of CuBr4^-2 (green) will be favored, and the equilibrium will shift towards the green side.

2. The color of the solution will appear more green. This is because the green CuBr4^-2 ions are formed as the equilibrium shifts towards the green side.

3. The solution will be cooler. This is because the reaction is exothermic, and according to Le Chatelier's Principle, adding KBr will shift the equilibrium towards the products, resulting in a decrease in the concentration of Cu(H2O)6^+2. Since there are fewer Cu(H2O)6^+2 ions present, less heat will be released during the reaction.

Answer 2

A)

1. Reaction will shift rightwards towards the products.

2. It will turn green.

3. The solution will be cooler..

B) It will turn green.

Step-by-step explanation:

Hello,

In this case, for the stated equilibrium:

`heat + Cu(H_2O)_6 ^(+2) (blue) + 4Br^- \rightleftharpoons 6H_2O + CuBr_4^(-2) (green)`

In such a way, by thinking out the Le Chatelier's principle, we can answer to each question:

A)

1. If potassium bromide, which adds bromide ions, is added more reactant is being added to the solution, therefore, the reaction will shift rightwards towards the products.

2. The formation of the green complex is favored, therefore, it will turn green.

3. The solution will be cooler as heat is converted into "cold" in order to reestablish equilibrium.

B) In this case, as the heat is a reactant, if more heat is added, more products will be formed, which implies that it will turn green.

Regards.