Consider the exothermic reaction CoCl42-(aq) + 6 H2O(l) Co(H2O)62+(aq) + 4 Cl -(aq). Will the equilibrium concentration of CoCl42- increase or decrease when the following changes occur?
a) HCl is added.
(b) Co(NO3)2 is added.
both of those compounds are not even in the equation?? how am i suppose to know?
increase
Apologies for the confusion. The equilibrium concentration of CoCl42- will not be directly affected by the addition of HCl or Co(NO3)2 since they are not part of the balanced equation.
In the exothermic reaction CoCl42-(aq) + 6 H2O(l) Co(H2O)62+(aq) + 4 Cl-(aq), only the concentrations of the species involved in the reaction will impact the equilibrium.
If you have any other questions, feel free to ask!
In order to determine how the equilibrium concentration of CoCl42- will be affected by the changes mentioned in part (a) and (b), we can use the principles of Le Chatelier's principle.
(a) HCl is added:
Although HCl is not directly mentioned in the chemical equation, it consists of Cl- ions, which are represented in the equation as products.
When HCl is added, more Cl- ions are introduced into the system. According to Le Chatelier's principle, the system will try to counteract this increase in Cl- ions by shifting the equilibrium to the left, i.e., toward the reactants. This means that more CoCl42- will be formed in order to consume the excess Cl- ions, resulting in an increase in the equilibrium concentration of CoCl42-.
(b) Co(NO3)2 is added:
Similarly, Co(NO3)2 consists of Co2+ ions. Although Co(NO3)2 is not directly mentioned in the equation, it introduces Co2+ ions into the system. According to Le Chatelier's principle, the system will react to counteract the increase in Co2+ ions by shifting the equilibrium to the left, i.e., toward the reactants. As a result, more CoCl42- will be formed to consume the excess Co2+ ions, leading to an increase in the equilibrium concentration of CoCl42-.
In summary, both the addition of HCl and Co(NO3)2 will cause an increase in the equilibrium concentration of CoCl42-. This is because the system will shift the equilibrium position to the reactant side to counteract the increase in Cl- and Co2+ ions, respectively.