Chapter 2: Problem 15
On doubling the concentration of reactant, the rate of reaction triples. Find the reaction order.
Short Answer
Expert verified
The reaction order is n = log(3) / log(2).
Step by step solution
01
Understanding the Given Information
The exercise states that when the concentration of the reactant is doubled, the rate of reaction triples. Mathematically, this can be represented as: if the initial concentration is [A], then the new concentration is 2[A], and if the initial rate is R, the new rate is 3R.
02
Applying the Rate Law to Reaction Order
The reaction rate for a reaction with respect to a reactant A can generally be expressed as: rate = k[A]^n, where k is the rate constant and n is the reaction order. Thus, we can create two equations: 1) Initial rate: R = k[A]^n 2) Rate with doubled concentration: 3R = k(2[A])^n.We then solve for n by dividing the second equation by the first equation to eliminate k.
03
Dividing the Rate Equations
Dividing the new rate equation by the initial rate equation gives: 3R / R = (k(2[A])^n) / (k[A]^n).Simplifying this yields 3 = 2^n. We now need to solve for n.
04
Solving for the Reaction Order
To find the value of n that satisfies the equation 3 = 2^n, we take the logarithm of both sides. Using logarithms, the equation becomes: log(3) = n * log(2).Solving for n gives n = log(3) / log(2), which can be calculated with a scientific calculator or logarithm tables.
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with Vaia!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Chemical Kinetics
Chemical kinetics is the study of the rates at which chemical reactions occur and the factors that affect those rates. This branch of chemistry is crucial for understanding reaction mechanisms, predicting reaction outcomes, and designing chemical processes. Fundamental to kinetics is the rate of reaction, which quantifies how quickly reactants transform into products over time.
Variables such as temperature, pressure, concentration of reactants, and catalysts can significantly affect reaction rates. Kinetics allows chemists to probe these variables by developing mathematical models that correlate them with the rate of reaction. Understanding kinetics can also guide chemists on how to control and optimize reactions for industrial applications, from pharmaceutical manufacturing to the food industry.
Variables such as temperature, pressure, concentration of reactants, and catalysts can significantly affect reaction rates. Kinetics allows chemists to probe these variables by developing mathematical models that correlate them with the rate of reaction. Understanding kinetics can also guide chemists on how to control and optimize reactions for industrial applications, from pharmaceutical manufacturing to the food industry.
Rate of Reaction
The rate of reaction measures the speed at which reactants are converted to products in a chemical reaction. It's a key concept in chemical kinetics as it helps us understand how quickly a reaction progresses. Quantitatively, the reaction rate can be described as the change in concentration of a reactant or product per unit time.
For example, if a reaction involving reactant A has a high rate, this means that A is being consumed rapidly to form the products. In the exercise provided, upon doubling the concentration of the reactant, the reaction rate triples, illustrating a direct, but non-proportional, relationship between the concentration of a reactant and the rate at which the reaction proceeds.
For example, if a reaction involving reactant A has a high rate, this means that A is being consumed rapidly to form the products. In the exercise provided, upon doubling the concentration of the reactant, the reaction rate triples, illustrating a direct, but non-proportional, relationship between the concentration of a reactant and the rate at which the reaction proceeds.
Rate Law
Rate law, also known as the rate equation, is a mathematical expression that relates the rate of a chemical reaction to the concentration of the reactants. It takes the general form of \( \text{rate} = k[A]^n \), where \( k \) is the rate constant, \( [A] \) represents the concentration of reactant A, and \( n \) is the reaction order. The rate constant \( k \) is a proportionality factor that is specific to each chemical reaction at a given temperature.
The reaction order \( n \) tells us how the rate of the reaction depends on the concentration of the reactant. In the exercise, finding the reaction order involved observing that tripling the rate results from doubling the concentration, which leads to the equation \( 3 = 2^n \). The value of \( n \) indicates the sensitivity of the rate to concentration changes and is usually determined experimentally. Using logarithms to solve for \( n \) in this equation, we can determine the reaction order and thus fully describe the rate law for the given reaction.
The reaction order \( n \) tells us how the rate of the reaction depends on the concentration of the reactant. In the exercise, finding the reaction order involved observing that tripling the rate results from doubling the concentration, which leads to the equation \( 3 = 2^n \). The value of \( n \) indicates the sensitivity of the rate to concentration changes and is usually determined experimentally. Using logarithms to solve for \( n \) in this equation, we can determine the reaction order and thus fully describe the rate law for the given reaction.