Oxidation-Reduction Reactions

Oxidation

an increase in oxidation number (aka: becomes less negative b/c of a loss of electrons)

Reduction

a decrease in oxidation number (aka: becomes more negative b/c of a gain in electrons)

Oxidizing Agents

-the ion or molecule that accepts the electrons
- this is the one that goes through reduction

Reducing Agents

-the ion or molecule that donates the electrons
-this is the one that goes through oxidation

Oxid. # of an element

when an element is the only one in a substance, such as Cl2 or P4, then the oxidation number is 0

Oxid. #s in monatomic ion

the oxidation number is equal to the charge of the ion
ex.in NaCl, Na+ has oxid. # of +1, and Cl- has oxid. # of -1

Elements With Constant Oxid. #

Hydrogen in compounds: +1
Oxygen in compounds: -2 (except in peroxide)
Group 1Metals =+1
Group 2 Elements=+2

Charge

charge of ions must add up to the overall charge of the ion or molecule