4.9 Oxidation-Reduction (Redox) Reactions

Balanced chemical equations for redox reactions can be constructed from what?

Half-reactions

What happens to a substance during oxidation?

Loses electrons

What happens to a substance during reduction?

Gains electrons

Equations that show either oxidation or reduction separately:

Half-reaction

What happens to electrons during an oxidation half-reaction?

Lost

Where do electrons appear during an oxidation-half reaction?

Right side of equation

What happens to electrons during a reduction half-reaction?

Gained

Where do electrons appear during a reduction half-reaction?

Left side of equation

What should a half-reaction be balanced in terms of?

Atoms and charge

What must the number of electrons lost in the oxidation half-reaction be equal to?

The number of electrons gained in the reduction half-reaction

How to cancel out the electrons on both sides of the equation of a redox reaction?

By multiplying a half-reaction by a certain number

What cancels out on both sides when the two half-reactions are added together?

Electrons

What is the result of adding the two half-reactions together?

The overall balanced oxidation-reduction equation

What should a redox equation be balanced in terms of?

Atoms and charge