REDOX

Oxidation

Is

Loss of electrons

Reduction

Is

Gain of electrons

• In an overall reaction, oxidation and reduction must go together 
• electron gain must equal the electron loss in the complete and fully balanced equation
• An electron acceptor is an oxidising agent and therefore gets reduced in its action, so there is a decrease in the oxidation number/state of one of the atoms of the oxidising agent.
• An electron donor is a reducing agent and therefore gets oxidised in the process, so there is an increase in the oxidation number/state of one of the atoms of the reducing agent.

the oxidation state can be defined as:

 the number of electrons which must be added or removed to leave the element in its electrically neutral elemental state. 

• The oxidation number of anything in elemental form is 0.
• Fluorine is assigned an oxidation number of -1 in compounds (Fl -1)
• Oxygen is assigned an oxidation number of -2 in compounds (O -2)
• Hydrogen is assigned an oxidation of +1 in compounds (H +1)
• Group I elements (Alkali Metals) are assigned an oxidation number of +1 in compounds (G1 +1)
• Group II elements (Alkaline-earth metals) are assigned an oxidation number of +2 in compounds (G2 +2)
• Any monatomic ion has an oxidation number equal to its charge
• The sum of the oxidation numbers of all the atoms in a formula equals the electrical charge shown with the formula

-Elements in the -s block will be oxidised (loss of electrons)

-This makes them reducing agents

-Most p-block elements have both positive and negative oxidation states.
-The maximum is the last digit of the group number (except for oxygen and fluorine for which the maximum is 0).

-The minimum is the Group Number - 18