REDOX Reactions

Oxidation – Reduction

Oxidation – Reduction Reaction

These reactions involve a transfer of electrons

Half reactions MUST occur simultaneously

Oxidation – loss of electronsOxidizing agent – a substance that

has the potential to cause another substance to be oxidized

Reduction – involves the gain of electronsReducing agent – a substance that

has the potential to cause another substance to be reduced (gain electrons)

Oxidation – Reduction Reaction

The oxidation number of a pure element is 0The oxidation number of a monatomic ion

equals the charge on the ionThe more electronegative element in a

binary compound is assigned the number equal to the charge it would have it were an ion

The oxidation number of fluorine in a compound is always -1

Oxygen has an oxidation number of -2 unless it is combined with Fluorine, in which it is +1 or +2, or it is in a peroxide, in which it is -1

Oxidation States

Hydrogen’s oxidation state in most of its compound is +1, unless it is combined with a metal, in which case it is -1

In compounds, Group 1 and Group 2 elements and aluminum have oxidation numbers of +1, +2, and +3 respectively

The sum of the oxidation numbers of all atoms in a neutral compound in 0

The sum of the oxidation numbers of all atoms in a polyatomic ion equals the charge of the ion

Oxidation States

OxidationOxidation is the process in which atoms

or ions of an element experience an increase in oxidation states

2 Na (s) + Cl2 (g) 2 NaCl(s)Sodium undergoes an oxidation process

because the sodium atoms loses an electron and become a sodium ion – sodium is an oxidized to a sodium ions

Electrons are on the right side of the arrow)

A species whose oxidation number increases is oxidized

0 +1

Na Na+ + e-

ReductionReduction is the process in which the

oxidation state of an element decreases 2 Na (s) + Cl2 (g) 2 NaCl(s)

 Each chlorine atom accepts an electrons and becomes a chloride ion

Electrons are on the left side of the arrow

Cl2 + 2e- 2Cl-

A species that undergoes a decrease in oxidation state is reduced

Lose GainElectronsElectronsOxidation Reduction“Leo” the lion says “Ger”

Oxidation – Reduction Reaction