Muhammad Fahad Ansari 12IEEM14

2. Presentation. BY;
Muhammad Fahad Ansari
12IEEM14

3. PRESENTATION TOPIC
OXIDATION – REDUCTION REACTIONS

4. OXIDATION – REDUCTION REACTIONS
Chemical reaction involves an electron
exchange between the reactants. one
substances loses electrons and another
substance gains electrons or gains a
greater share of them these reactions are
called oxidation – reduction reactions.

5. OXIDATION; is the loss of
electrons and
REDUCTION; is the gain of
elecrrons

6. for example:
A c-x bond . If when the bond is broken , the
electrons are left with c, c takes on a negative charge
and is called a carbon anion.
If the electrons leave with x, then c is left with a
positive charge and is a carbon cation

7. OXIDIZING AGENT;
Substances that causes another substance to lose
electrons
REDUCING AGENT;
Substance that loses electrons in a chemical reaction; it
reduces another substance by losing electrons to it

8. CHEMICAL REACTIONS:
Example:
REACTANTS PRODUCT
2Na + Cl2 2Na+ Cl-
LOSS GAIN
Oxidized Reduced
Reducing Agent Oxidizing Agent

9. Gain and Loss of Hydrogen
• An alternative approach is to describe oxidation as the loss of
hydrogen and reduction as the gaining of hydrogen.
• 2CH4 + 2O2 -> CO2 + 2H2O
With this approach it is clear that the carbon is oxidized (loses all
four hydrogens) and that part of the oxygen is reduced (gains
hydrogen).
• Another reaction where the hydrogen approach makes
things clearer is the passing of methanol over a hot
copper gauze to form formaldehyde and hydrogen gas
CH3OH -> CH2O + H2

10. Oxidation Number or Oxidation State
Reflects the number of electrons lost or gained in
relation to the elemental state.
For example: Na0 , Mg0 , and so on.
For example: Na1+, Mg2+

11. Thanks