Consider the exothermic reaction CoCl 2-1aq2 + 6 H O1l2 ∆ Co1H O2 2 + 1aq2 + 4 Cl-1aq2 which interconverts the blue CoCl 2- ion and the pink Co 2 +CoCl 2- increase or decrease when the following changes occur?(c) The solution is diluted with water.

Verified step by step guidance

1. Identify the reaction given: \[ \text{CoCl}_4^{2-} (\text{aq}) + 6 \text{H}_2\text{O} (\text{l}) \rightleftharpoons \text{Co(H}_2\text{O})_6^{2+} (\text{aq}) + 4 \text{Cl}^- (\text{aq}) \]
2. Recognize that this is an exothermic reaction, meaning it releases heat.
3. Understand that diluting the solution with water affects the concentration of the ions involved in the equilibrium.
4. Apply Le Chatelier's Principle, which states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change.
5. Determine that adding water decreases the concentration of all aqueous species, and the equilibrium will shift to the side with more particles to counteract the dilution, affecting the color change.

Key Concepts

Le Chatelier's Principle

Le Chatelier's Principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change. In the context of the given reaction, diluting the solution with water alters the concentration of the reactants and products, prompting the system to adjust in a way that minimizes the effect of dilution.

Exothermic Reactions

Exothermic reactions are chemical processes that release heat to the surroundings. In the provided reaction, the formation of Co(H2O)6^2+ and Cl^- ions from CoCl2 and water is exothermic, meaning that the reaction releases energy. Understanding this helps predict how temperature changes can affect the equilibrium position.

Color Change in Coordination Complexes

The color change observed in coordination complexes, such as the transition from blue CoCl2^- to pink Co(H2O)6^2+, is due to the different ligands surrounding the metal ion. The nature of the ligands and their arrangement affects the d-orbital splitting, which in turn influences the absorption of light and the perceived color. This concept is crucial for interpreting the effects of dilution on the equilibrium state.