How does the rate law show how concentration changes affect the rate of reaction?
A. The rate is expressed as the sum of the concentrations of reactants raised to some power.
B. The rate is expressed as the difference between the concentrations of reactants.
C. The rate is expressed as a ratio of the concentrations of reactants raised to some power.
D. The rate is expressed in terms of concentrations of the reactants raised to some power.
Answer (1)
The rate law expresses the rate of a reaction as a function of the concentrations of the reactants.
Each reactant's concentration is raised to a power, which represents the order of the reaction with respect to that reactant.
The rate law is a product of the concentrations, each raised to its respective power, multiplied by the rate constant.
Therefore, the rate is expressed in terms of concentrations of the reactants raised to some power: D .
Explanation
Understanding the Rate Law The rate law is a mathematical expression that shows how the rate of a chemical reaction depends on the concentration of the reactants. It generally takes the form: r a t e = k [ A ] m [ B ] n where:
rate is the rate of the reaction,
k is the rate constant,
[A] and [B] are the concentrations of the reactants,
m and n are the orders of the reaction with respect to reactants A and B, respectively.
How Concentration Affects Rate The rate law expresses the rate of a reaction as a function of the concentrations of the reactants, each raised to a certain power (the order of the reaction with respect to that reactant). The rate constant, k, is a proportionality constant that reflects the intrinsic speed of the reaction.
Analyzing the Options Now, let's analyze the given options: OA. The rate is expressed as the sum of the concentrations of reactants raised to some power. - This is incorrect because the rate law involves the product of concentrations, not the sum. OB. The rate is expressed as the difference between the concentrations of reactants. - This is incorrect because the rate law involves the product of concentrations, not the difference. OC. The rate is expressed as a ratio of the concentrations of reactants raised to some power. - This is incorrect because the rate law involves the product of concentrations, not a ratio. OD. The rate is expressed in terms of concentrations of the reactants rised to some power. - This is the correct description of the rate law.
Final Answer Therefore, the correct answer is that the rate is expressed in terms of concentrations of the reactants raised to some power.
Examples
In a chemical manufacturing plant, understanding the rate law for a particular reaction is crucial for optimizing production. For example, if the rate law shows that the reaction rate is highly dependent on the concentration of a specific reactant, the plant operators can increase the concentration of that reactant to speed up the reaction and increase production output. This knowledge helps in fine-tuning the reaction conditions to achieve the desired production rate efficiently and safely.
