1.7- redox

what is oxidation

loss of electrons

what is reduction

gain of electrons

what is an oxidising agent

electron acceptor (gets reduced)

what is a reducing agent

electron doner (gets oxidised)

rules for assigning oxidation numbers

1. oxidation state of any pure element is 0

2. oxidation state of ion is the charge (if diatomic divide by two for each atom)

3. oxidation numbers of elements in a compound add up to 0

4. In a polyatomic ion the sum of the individual oxidation numbers of the elements adds up to the charge on the ion

oxidation state of hydrogen

+1 if bonded to a non-metal

-1 if bonded to a metal as more electronegative

oxidation state of oxygen

-2 except in peroxides (H2O2 ) where it is -1 and in compounds with fluorine

rules for balancing half/redox equations

1. balance all atoms except O or H

2. balance O with H2O

3. Balance H with H+

4. Balance charge with e-

What is a redox reaction?

electrons move between atoms

oxidation and reduction happens at same time

what is a disproportionate reaction

one atom is reduced and oxidised