Changing the concentration of reactants affects the rate of reaction due to the collision theory. According to the collision theory, the rate of a chemical reaction depends on the frequency of collisions between reactant molecules. When the concentration of reactants is increased, there are more molecules present in a given volume, which leads to a higher chance of collisions and, consequently, a faster reaction rate.The impact of changing the concentration of reactants on the overall profitability of a chemical reaction depends on several factors, including the cost of reactants, the value of the products, and the efficiency of the reaction process.1. Cost of reactants: If increasing the concentration of reactants leads to a faster reaction rate, it may be possible to produce more products in a shorter amount of time. However, this may also require a higher initial investment in reactants, which could impact profitability.2. Value of products: If the products of the reaction are valuable, a faster reaction rate due to increased reactant concentration may lead to higher profits, as more products can be produced and sold in a shorter amount of time.3. Efficiency of the reaction process: Increasing the concentration of reactants may lead to a faster reaction rate, but it could also result in a less efficient process if the reaction becomes too difficult to control or if side reactions occur. In such cases, the overall profitability of the reaction may be negatively impacted.In conclusion, changing the concentration of reactants can affect the rate of reaction and may have both positive and negative impacts on the overall profitability of a chemical reaction. It is essential to consider the specific reaction, the costs of reactants, and the value of the products when determining the optimal concentration for a given process.