Question

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 pre-dominates. 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
2. When the temperature is decreased the equilibrium constant, K:____.
A. Increases
B. Decreases
C. Remains the same.
3. When the temperature is decreased the equilibrium concentration of Co2:______.
A. Increases
B. Decreases
C. Remains the same.

Answer 1

Answer:

1. This reaction is (A) Exothermic .

2. When the temperature is decreased the equilibrium constant, K: (A) Increases

3.When the temperature is decreased the equilibrium concentration of Co2: (A) Increases

Explanation:

$CoCl4^2-(aq) Co_2+(aq) + 4Cl^-(aq)$

1. The pink color predominates at low temperatures, indicating that the commodity is preferred.

This is a reaction that is exothermic.

2. As the decrease in the temperature , the equilibrium constant , K ;

      equilibrium constant = $\frac{product}{reactant}$ =$\frac{[CO^2^+][Cl^-^4]}{CoCl^2^-_4}$

As the temperature drops, the concentration of$Cl^-$ and $CO^2^+$ rises, and K rises as well , thus it increases .

3. The equilibrium concentration of $CO^2^+$ decreases as the temperature decreases:

When the temperature is lowered, the equilibrium shifts to the right , that is it increases.