AQA A-Level Chemistry 7405
Atomic Structure
Amount of Substance
Bonding
Energetics and Thermodynamics
Kinetics
Chemical Equilibria
Redox and Electrochemistry
Acids and Bases
Periodicity and Group Chemistry
Period 3 Elements and Their Oxides
Transition Metals
Introduction to Organic Chemistry
Hydrocarbons
Halogenoalkanes, Alcohols and Organic Analysis
Carbonyls, Carboxylic Acids and Derivatives
Aromatic Chemistry and Amines
Polymers, Amino Acids, Proteins and DNA
Organic Synthesis, NMR and Chromatography
Kinetics
- 9 subtopics
- 27 things to know
- Papers 2 and 3
What Kinetics covers
Kinetics is examined on Papers 2 and 3. The first half explains rate qualitatively through collisions and the Maxwell-Boltzmann distribution; the second half makes it quantitative with rate equations, the Arrhenius equation, and what the rate-determining step reveals about a mechanism.
Where it is assessed
Papers 2 and 3
Organic and the physical chemistry behind it, then the synoptic paper.
Check the AQA specification ↗The 9 subtopics
Each one has its own page.
- Collision Theory and Activation EnergyThe two conditions a successful collision needs, and what activation energy is.Open →
- Maxwell-Boltzmann Distribution and the Effect of TemperatureReading the distribution curve, and what raising the temperature does to the molecules beyond the activation energy.Open →
- Effect of Concentration and Pressure, and CatalystsCollision frequency, and how a catalyst provides an alternative route of lower activation energy.Open →
- Rate Equations: The Rate Equation and Orders of ReactionThe form rate = k[A]ᵐ[B]ⁿ, what the rate constant means, and order with respect to a reactant and overall.Open →
- Rate Equations: The Effect of Concentration on RateWhat doubling or tripling a concentration does to the rate at zero, first and second order.Open →
- The Rate Constant and the Arrhenius EquationThe units of k, and using the Arrhenius equation and its logarithmic form.Open →
- Determining Rate Equations: The Initial Rates MethodFinding orders by comparing initial rates across experiments where one concentration is changed at a time.Open →
- Determining Rate Equations: Continuous MonitoringFollowing one reaction throughout by colorimetry, conductivity or gas volume, taking gradients from the concentration-time graph, and reading orders from a rate-concentration graph.Open →
- Rate Equations and Reaction MechanismsThe rate-determining step, and what a species appearing in the rate equation tells you.Open →
What you need to know
Answer each one before you reveal it.
What happens to the rate when the concentration of a zero, first or second order reactant is doubled?
What two conditions must be met for a reaction to occur according to collision theory?
What does a Maxwell-Boltzmann distribution show?
What is represented on the x-axis of a Maxwell-Boltzmann distribution curve?
How does increasing the concentration of a reactant affect collision frequency?
Why does increasing concentration increase the rate of a reaction?
What is the general form of a rate equation?
What is meant by the order of reaction with respect to a particular reactant?
What happens to the rate of reaction if the concentration of a zero order reactant is doubled?
What is the rate constant in a rate equation?
What are the units of the rate constant dependent upon?
What is the initial rates method used to determine?
In the initial rates method, what is measured at the very start of a reaction?
What is the continuous monitoring method used to determine?
In the continuous monitoring method, what is measured throughout the course of a reaction?
What is the rate-determining step of a reaction?
How does the rate-determining step relate to the overall rate equation?
What is meant by the term "activation energy"?
What is represented on the y-axis of a Maxwell-Boltzmann distribution curve?
How does increasing the pressure of a gaseous reaction mixture affect collision frequency?
What is the overall order of a reaction?
What happens to the rate of reaction if the concentration of a first order reactant is doubled?
How do you determine the units of the rate constant for a given rate equation?
Why is the initial rate measured rather than the rate at a later time in the initial rates method?
What type of graph is plotted to determine the order of reaction using the continuous monitoring method?
If a species appears in the rate equation, what can be concluded about its involvement in the mechanism?
Take Kinetics further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Activation energy vs A catalyst
Activation energy: the minimum energy a colliding pair must have for a reaction to occur. A catalyst: a substance that provides an alternative route of lower energy without being used up.
The order of reaction vs The rate constant
The order of reaction: the power to which a reactant's concentration is raised in the rate equation. The rate constant: the proportionality constant linking the rate to those concentration terms.
A zero order reactant vs A first order reactant
A zero order reactant: one whose concentration has no effect at all on the rate. A first order reactant: one for which doubling the concentration doubles the rate.
Questions from this topic
Each one with the model answer underneath.
- 1
What two conditions must be met for a reaction to occur according to collision theory?
Model answer
Particles must collide with energy equal to or greater than the activation energy, and they must collide with the correct orientation.
- 2
What is meant by the term "activation energy"?
Model answer
The minimum energy that colliding particles must have for a reaction to occur.
- 3
Why do particles need to collide with a minimum amount of energy for a reaction to occur?
Model answer
This minimum energy is required to break the bonds in the reactants and initiate the reaction.
- 4
What happens if colliding particles do not have energy equal to or greater than the activation energy?
Model answer
The particles bounce apart without reacting.
- 5
Besides having sufficient energy, what other requirement must be met for a successful collision?
Model answer
The particles must collide with the correct orientation.
- 6
Why is correct orientation important during a collision?
Model answer
The reactive parts of the molecules must come into contact for bonds to break and new bonds to form.
What is inside Levo
Six ways to work the same material.
Kinetics revision questions
- What does Kinetics cover in AQA A-Level Chemistry?
- 9 subtopics: collision theory and activation energy, maxwell-boltzmann distribution and the effect of temperature, effect of concentration and pressure, and catalysts, rate equations: the rate equation and orders of reaction, rate equations: the effect of concentration on rate, the rate constant and the arrhenius equation, determining rate equations: the initial rates method, determining rate equations: continuous monitoring and rate equations and reaction mechanisms. Each one has its own page with questions and model answers.
- How is Kinetics organised?
- By the AQA 7405 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Kinetics, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
Or £46 a year, about £3.83 a month. Cancel anytime.