Transfer of electrons
Oxidation state
Rule number 1
Rule number 2
Rule number 3
Rule number 4
Rule number 5
Rule number 6
Rule number 7
Rule number 8
Let’s practice…
Determine the oxidation numbers for
the atoms in the compound NaCl.
Determine which atom will have a positive or negative
oxidation number.
Determine the oxidation number for each atom
Check whether the oxidation numbers add up to
the overall charge
Give the oxidation number of sulfur in a
sulphate ion
Determine which atom will have a positive or negative
oxidation number by looking at the electronegativity
values.
Determine the oxidation number for each atom.
Determine the oxidation number of sulfur by using the
fact that the oxidation numbers of the atoms must add
up to the charge on the molecule
Determine the oxidation states of the
elements K and Br on both the reactant
and product side of the following reaction:
2K + Br2 →2KBr
In the product determine which atom will have a
positive or negative oxidation number by looking at the
electronegativity values
Use the valency of the elements in the product to
determine the oxidation numbers.
Check whether the oxidation numbers add up to the
charge on the compound
Redox Reactions
Reduction-Oxidation
Let’s look at an example of this…
(2x)
Half-reaction
The oxidation or reduction reaction part
of a redox reaction. It is obtained by
considering the change in oxidation
states of the individual substances that
are involved in the redox reaction
Oxidation is the loss of electrons and leads to an increase
in oxidation number
Reduction is the gain of electrons and leads to a decrease
in oxidation number
OILRIG
Oxidation Is Loss of electrons
and Reduction Is Gain.