The effect of increasing temperature on the formation of a complex ion in a chemical equilibrium reaction can be understood using Le Chatelier's principle and the Van't Hoff equation. Le Chatelier's principle states that if a system at equilibrium is subjected to a change in temperature, pressure, or concentration of reactants or products, the system will adjust to counteract the change and establish a new equilibrium.Let's consider a general complex ion formation reaction:M^n+ + xL MLx^n-x +Here, M^n+ is a metal ion with a charge of n+, L is a ligand, and MLx^n-x + is the complex ion formed. The equilibrium constant for this reaction is given by:K = [MLx^n-x +] / [M^n+] [L]^x Now, let's consider the effect of increasing temperature on this reaction. According to the Van't Hoff equation, the relationship between the equilibrium constant K and temperature T is given by:d ln K / d 1/T = -H / Rwhere H is the standard enthalpy change of the reaction, and R is the gas constant.If the formation of the complex ion is an endothermic reaction H > 0 , increasing the temperature will favor the forward reaction, leading to the formation of more complex ions. In this case, the equilibrium constant K will increase with increasing temperature.On the other hand, if the formation of the complex ion is an exothermic reaction H < 0 , increasing the temperature will favor the reverse reaction, leading to the dissociation of the complex ions. In this case, the equilibrium constant K will decrease with increasing temperature.In summary, the effect of increasing temperature on the formation of a complex ion in a chemical equilibrium reaction depends on the enthalpy change of the reaction. If the reaction is endothermic, increasing temperature will favor the formation of the complex ion, while if the reaction is exothermic, increasing temperature will favor the dissociation of the complex ion.