Textbook Question
The relative rates of the reaction A + B S AB in vessels(1)–(3) are 4:4:1. Red spheres represent A molecules, andblue spheres represent B molecules.(1)-(3) (a) What is the order of the reaction in A and B?
510
views
Ch.14 - Chemical Kinetics
McMurry8th EditionChemistryISBN: 9781292336145
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch.1 - Chemical Tools: Experimentation & Measurement143
- Ch.2 - Atoms, Molecules & Ions134
- Ch.3 - Mass Relationships in Chemical Reactions149
- Ch.4 - Reactions in Aqueous Solution157
- Ch.5 - Periodicity & Electronic Structure of Atoms92
- Ch.6 - Ionic Compounds: Periodic Trends and Bonding Theory73
- Ch.7 - Covalent Bonding and Electron-Dot Structures47
- Ch.8 - Covalent Compounds: Bonding Theories and Molecular Structure51
- Ch.9 - Thermochemistry: Chemical Energy104
- Ch.10 - Gases: Their Properties & Behavior138
- Ch.11 - Liquids & Phase Changes43
- Ch.12 - Solids and Solid-State Materials56
- Ch.13 - Solutions & Their Properties98
- Ch.14 - Chemical Kinetics79
- Ch.15 - Chemical Equilibrium107
- Ch.16 - Aqueous Equilibria: Acids & Bases94
- Ch.17 - Applications of Aqueous Equilibria125
- Ch.18 - Thermodynamics: Entropy, Free Energy & Equilibrium66
- Ch.19 - Electrochemistry130
- Ch.20 - Nuclear Chemistry73
- Ch.21 - Transition Elements and Coordination Chemistry122
- Ch.22 - The Main Group Elements155
- Ch.23 - Organic and Biological Chemistry43
Chapter 14, Problem 44
The following pictures represent the progress of a reaction in which two A molecules combine to give a more complex molecule A2, 2 AS A2. 
(b) What is the rate law?
Verified step by step guidance1
Step 1: Identify the reaction given: 2A -> A2.
Step 2: Observe the images provided, noting the number of A molecules at each time interval (0 min, 1 min, 2 min).
Step 3: Determine the change in concentration of A molecules over time by counting the number of A molecules at each time interval.
Step 4: Use the rate law expression for a reaction of the form 2A -> A2, which is rate = k[A]^2, where k is the rate constant.
Step 5: Conclude that the rate law for this reaction is rate = k[A]^2, indicating a second-order reaction with respect to A.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Rate Law
The rate law is an equation that relates the rate of a chemical reaction to the concentration of its reactants. It is typically expressed in the form rate = k[A]^m[B]^n, where k is the rate constant, and m and n are the orders of the reaction with respect to reactants A and B, respectively. Understanding the rate law is crucial for predicting how changes in concentration affect the reaction rate.
Recommended video:
Guided course
01:52
Rate Law Fundamentals
Reaction Order
Reaction order refers to the power to which the concentration of a reactant is raised in the rate law. It indicates how the rate of reaction is affected by the concentration of that reactant. For example, a first-order reaction means that the rate is directly proportional to the concentration of one reactant, while a second-order reaction indicates that the rate is proportional to the square of the concentration of that reactant.
Recommended video:
Guided course
00:36Average Bond Order
Molecularity
Molecularity is the number of reactant molecules involved in an elementary reaction step. It can be unimolecular (one molecule), bimolecular (two molecules), or termolecular (three molecules). In the context of the given reaction, where two A molecules combine to form A2, the reaction is bimolecular, which is important for determining the rate law and understanding the mechanism of the reaction.
Recommended video:
Guided course
02:38Molecular Polarity
Related Practice
Textbook Question
What is the molecularity of each of the following elementary reactions?(a) (b) (c)
942
views
Textbook Question
Consider the first-order decomposition of A molecules (red spheres) in three vessels of equal volume. (1)-(3) (c) How will the rates and half-lives be affected if the volume of each vessel is decreased by a factor of 2?
472
views
Textbook Question
Consider a reaction that occurs by the following mechanism:
A + BC → AC + B
AC + D → A + CD
The potential energy profile for this reaction is as follows:
(d) Is the reaction endothermic or exothermic? Add labels to the diagram that show the values of the energy of reaction ΔE and the activation energy Ea for the overall reaction.
523
views
Textbook Question
Consider the first-order decomposition of A molecules (red spheres) in three vessels of equal volume. (1)-(3)
(b) What are the relative half-lives of the reactions in vessels (1)–(3)?
583
views
Textbook Question
Consider the first-order reaction AS B in which A molecules(red spheres) are converted to B molecules (blue spheres).(a) Given the pictures at t = 0 min and t = 1 min, drawpictures that show the number of A and B moleculespresent at t = 2 min and t = 3 min.
766
views