The reaction between potassium iodide KI and lead nitrate Pb NO3 2 is a precipitation reaction that forms lead iodide PbI2 and potassium nitrate KNO3 . The balanced chemical equation for this reaction is:2 KI aq + Pb NO3 2 aq 2 KNO3 aq + PbI2 s The rate of reaction and selectivity in this reaction can be affected by changing the concentration of the reactants, KI and Pb NO3 2.1. Rate of Reaction:The rate of a chemical reaction is the speed at which reactants are converted into products. According to the collision theory, the rate of a reaction depends on the frequency and energy of collisions between reacting particles. As the concentration of reactants increases, the number of particles in the solution also increases, leading to a higher probability of collisions between the reactant particles.In the case of the reaction between KI and Pb NO3 2, increasing the concentration of either or both reactants will increase the rate of reaction. This is because there will be more KI and/or Pb NO3 2 particles in the solution, leading to a higher frequency of collisions and thus a faster formation of PbI2 and KNO3.2. Selectivity:Selectivity in a chemical reaction refers to the preference for the formation of one product over another when multiple products are possible. In the reaction between KI and Pb NO3 2, there is only one major product, PbI2, and the reaction is considered to be highly selective. However, if there were any side reactions or competing reactions, the selectivity could be affected by the concentration of the reactants.In general, increasing the concentration of reactants can sometimes lead to a change in selectivity if the reaction involves multiple pathways or competing reactions with different rate constants. However, in the case of the reaction between KI and Pb NO3 2, there is only one major pathway, and the selectivity remains high for the formation of PbI2 regardless of the concentration of the reactants.In summary, changing the concentration of reactants in the reaction between potassium iodide and lead nitrate will affect the rate of reaction, with higher concentrations leading to faster reaction rates. However, the selectivity for the formation of lead iodide remains high regardless of the concentration of the reactants, as there is only one major reaction pathway.