Redox reactions

Redox reactionsReduction – oxidation reaction

Electron transfer occurs

Reactant 1Reactant

2

e-

Undergoes oxidation

Undergoes reduction

This

is a

Rix

-Tab

le (o

r a

RED

OX

tabl

e)It helps you to write the oxidation and reduction half reactions.

The reaction between Zinc and Copper (II) sulphate

Zn atoms (atoms are always electrically neutral) loses two electrons, becoming positively charged

Zn-ions.

Zn Zn2+ + 2e-

Oxidation: electrons lost

Copper(II)sulphate consist of copper ions and sulfate ions. Electrons from the Zn-atoms are

transferred to the copper ions. The copper ions gain the electrons and copper atoms forms. They

combine to form a copper precipitate in the solution.

Cu2+ + 2e- Cu

Reduction: electrons gained

The sulphate ions are spectator ions.

Spectator ions are present in a reaction, without experiencing oxidation or reduction.

Slide 4: http://images.flatworldknowledge.com/averillfwk/averillfwk-fig19_002.jpg

A. Olivier; Physical Sciences Book 2 Chemistry 2nd edition 2013