Textbook Question
What are the units of k for each type of reaction?
a. first-order reaction
b. second-order reaction
c. zero-order reaction
1049
views
Ch.14 - Chemical Kinetics
Chapter 14, Problem 39a
A reaction in which A, B, and C react to form products is first order in A, second order in B, and zero order in C.
a. Write a rate law for the reaction.
Verified step by step guidance1
Identify the order of reaction with respect to each reactant: first order in A, second order in B, and zero order in C.
Recall that the rate law for a reaction is expressed as: \( \text{Rate} = k[A]^m[B]^n[C]^p \), where \( k \) is the rate constant, and \( m, n, \) and \( p \) are the orders of the reaction with respect to A, B, and C, respectively.
Substitute the given orders into the rate law expression: \( m = 1 \), \( n = 2 \), and \( p = 0 \).
Write the rate law using the substituted values: \( \text{Rate} = k[A]^1[B]^2[C]^0 \).
Simplify the rate law expression, noting that any term raised to the power of zero is equal to one: \( \text{Rate} = k[A][B]^2 \).
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
4mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Rate Law
The rate law of a chemical reaction expresses the relationship between the rate of the reaction and the concentration of its reactants. It is typically formulated as rate = k[A]^m[B]^n[C]^p, where k is the rate constant, and m, n, and p are the orders of the reaction with respect to each reactant. The orders indicate how the rate is affected by changes in concentration.
Recommended video:
Guided course
01:52
Rate Law Fundamentals
Order of Reaction
The order of a reaction refers to the power to which the concentration of a reactant is raised in the rate law. It can be determined experimentally and indicates how the rate of reaction changes with varying concentrations. For example, a first-order reaction in A means that doubling the concentration of A will double the reaction rate, while a second-order reaction in B means that doubling B will quadruple the rate.
Recommended video:
Guided course
00:36Average Bond Order
Zero-Order Reactions
In a zero-order reaction, the rate of reaction is constant and does not depend on the concentration of the reactant. This means that changes in the concentration of the zero-order reactant (in this case, C) have no effect on the reaction rate. Zero-order behavior often occurs when a reactant is saturated or when the reaction is limited by a factor other than concentration.
Recommended video:
Guided course
02:44Zero-Order Reactions
Related Practice
Textbook Question
This reaction is first order in N2O5: N2O5(g) → NO3(g) + NO2(g) The rate constant for the reaction at a certain temperature is 0.053/s. a. Calculate the rate of the reaction when [N2O5] = 0.055 M
531
views
Textbook Question
This reaction is first order in N2O5: N2O5(g) → NO3(g) + NO2(g) The rate constant for the reaction at a certain temperature is 0.053/s. b. What would the rate of the reaction be at the concentration indicated in part a if the reaction were second order? Zero order? (Assume the same numerical value for the rate constant with the appropriate units.)
2747
views
1
rank
Textbook Question
A reaction in which A, B, and C react to form products is first order in A, second order in B, and zero order in C. b. What is the overall order of the reaction?
422
views
Textbook Question
A reaction in which A, B, and C react to form products is first order in A, second order in B, and zero order in C c. By what factor does the reaction rate change if [A] is doubled (and the other reactant concentrations are held constant)? d. By what factor does the reaction rate change if [B] is doubled (and the other reactant concentrations are held constant)? e. By what factor does the reaction rate change if [C] is doubled? f. By what factor does the reaction rate change if the concentrations of all three reactants are doubled?
858
views
Textbook Question
A reaction in which A, B, and C react to form products is zero order in A, one-half order in B, and second order in C. a. Write a rate law for the reaction.
832
views