Unit 10
Redox and electrochemistry.
Electrons passed from one substance to another: oxidation and reduction, the reactivity series, cells and electrolysis.
Before this unit
The unit, lesson by lesson
Lessons
4 lessons · 25 practice questions · about 2 hours
Oxidation and reduction
Reactions in which electrons pass from one substance to another: who loses and who gains, where the electrons go in a cell, oxidation numbers, and why oxidation never happens alone.
The reactivity series
Why sodium skates over water and potassium catches fire, how metals are ranked by how readily they lose electrons, and what the ranking predicts: which metal pushes which out of solution, and which gives off hydrogen in acid.
Galvanic cells
How a redox reaction makes electricity: anode and cathode, voltage from standard potentials, why the poles can swap, how much voltage is lost inside the cell, and what the salt bridge does.
Batteries and electrolysis
A battery is a galvanic cell you can run backwards: what runs down as it discharges, what charging does, and how electrolysis makes metals and plates objects with them, gram by gram.