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 predominates. ... ... at high temperature the blue color is strong. ... if we represent the equilibrium as:...co2+(aq) + 4cl-(aq) cocl42-(aq) we can conclude that: 1. this reaction is:

a. exothermic
b. endothermic
c. neutral
d. more information is needed to answer this question.

Answer 1

b. Endothermic

Step-by-step explanation:

Hello,

By considering the equilibrium chemical reaction:

`Co^(+2)+4Cl^-<-->CoCl_4^(-2)`

The Le Chatelier's principle states that if the temperature for endothermic chemical reactions is increased the equilibrium will shift rightwards, in such a way, as at high temperatures the blue color, corresponding to the complex, predominates, this behavior assures the chemical reaction as endothermic.

Best regards.

Answer 2

Answer is: this reaction is b. endothermic, when heat is added to equilibrium, the position of equilibrium moves to right.
Chemical reaction: Co²⁺(aq) + 4Cl⁻(aq) ⇄ CoCl₄²⁻(aq).
According to Le Chatelier's Principle, the position of equilibrium moves to counteract the change, the position of equilibrium will move so that the concentration of products of chemical reaction increase if we increase temperature.