Increasing the concentration of reactants in a chemical reaction generally leads to an increase in the rate of the reaction. This is because a higher concentration of reactants results in a higher number of particles in the solution, which in turn increases the frequency of collisions between the reactant particles. According to the collision theory, more frequent collisions lead to a higher probability of successful collisions, which results in an increased rate of reaction.In the case of the reaction between potassium iodide KI and lead nitrate Pb NO3 2 in an aqueous solution, the reaction can be represented by the following balanced equation:2 KI aq + Pb NO3 2 aq 2 KNO3 aq + PbI2 s As the concentration of potassium iodide and lead nitrate is increased, the rate of reaction will also increase due to the higher frequency of collisions between the KI and Pb NO3 2 particles. This will result in the formation of potassium nitrate KNO3 and lead iodide PbI2 at a faster rate. The lead iodide will precipitate out of the solution as a yellow solid, which can be observed as an indication of the reaction progress.