Redox and Electrochemistry | AQA A-Level Chemistry (7405)
Redox and Electrochemistry
- 109 questions
- 7 subtopics
- Physical chemistry, drawn on by Paper 1 and Paper 2
- Paper 1, Paper 2 and Paper 3
Redox and electrochemistry is examined on Papers 1 and 3.
It begins with oxidation states and half-equations, then uses standard electrode potentials to predict which reactions run and to explain the cells that put them to work.
Sample questions from Redox and Electrochemistry
Answer each one closed book first, then open the answer.
-
Redox: Definitions and the Rules for Oxidation States
What oxidation state is assigned to uncombined elements?
Show the answer
Zero -
Redox: Definitions and the Rules for Oxidation States
What oxidation state is usually assigned to hydrogen in compounds?
Show the answer
+1 -
Redox: Identifying Oxidation and Reduction in a Reaction
What change in oxidation state indicates that an element has been reduced?
Show the answer
A decrease in oxidation state -
Redox: Identifying Oxidation and Reduction in a Reaction
Why must oxidation and reduction always occur together in a redox reaction?
Show the answer
Electrons lost by one species must be gained by another; electron transfer requires both a donor and an acceptor -
Half-Equations and Combined Redox Equations
What is the purpose of combining two half-equations?
Show the answer
To produce an overall redox equation showing the complete reaction. -
Half-Equations and Combined Redox Equations
When balancing half-equations in acidic solution, what species can be added to balance oxygen atoms?
Show the answer
Water (H₂O). -
Standard Electrode Potentials and the Hydrogen Electrode
What concentration of ions is specified for standard electrode potential measurements?
Show the answer
1.00 mol dm⁻³ -
Standard Electrode Potentials and the Hydrogen Electrode
What does a more negative standard electrode potential indicate about a species' tendency to be reduced?
Show the answer
A lesser tendency to be reduced (the species is more likely to be oxidised; stronger reducing agent)
The 7 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Redox: Definitions and the Rules for Oxidation States | Oxidation and reduction in terms of electrons, oxidising and reducing agents, and the rules for assigning oxidation states. | 14 |
| Redox: Identifying Oxidation and Reduction in a Reaction | Reading oxidation state changes off an equation, and building half-equations into a balanced overall equation. | 9 |
| Half-Equations and Combined Redox Equations | Writing half-equations and combining them into a balanced overall equation. | 15 |
| Standard Electrode Potentials and the Hydrogen Electrode | The standard hydrogen electrode, the conditions for measuring E°, and what the sign means. | 14 |
| Electrochemical Cells and EMF Calculations | Cell notation, the IUPAC convention, and calculating EMF from two electrode potentials. | 23 |
| Predicting Redox Reactions from Electrode Potentials | Using E° values to decide which species is oxidised, and why a feasible reaction may still be slow. | 14 |
| Commercial Cells and Fuel Cells | Lithium cells and hydrogen fuel cells, their electrode reactions, and the advantages and limitations of each. | 20 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
-
Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
-
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
-
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
AQA A-Level Chemistry Active Recall Guide
Every topic, not just this one. 2,442 questions with their answers.