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: +(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.