Answer:
In a REDUCTION reaction, a molecule gains an electron. Conversely an OXIDATION reaction Involves the loss of an electron from a
molecule.
Explanation:
A Chemical reaction is defined as a reaction in which new substances are formed from the combination of two or more chemical substances. There are different types of chemical reaction which include the OXIDATION and REDUCTION (redox) reaction among many others.
Oxidation and reduction reactions go hand in hand( that is, they are complementary) and that is why they are referred to as redox reaction.
Oxidation is defined as a reaction which Involves the loss of an electron from a
molecule. This leads to increase in oxidation number This can be seen in the example below of reaction between iron and hydrogen peroxide:
2Fe2+ + H2O2 + 2H+ → 2Fe3+ + 2H2O
Here there is loss of electron of Fe2+( iron{II}ion to Fe3+( iron{III}ion) and increase in oxidation number from 2+ to 3+.
(Fe2+ → Fe3+ + e–)
In REDUCTION reaction, a molecule gains an electron. This reaction also leads to decrease in oxidation number. This can be seen in the example below of reaction between zinc and copper sulphate solution:
Zn (s) + CuSO4 (aq) → ZnSO4 (aq) + Cu (s)
Cu2+ + 2e– → Cu
Here the Cu2+ ion in the gained two electrons ( 2e–) to be reduced to copper metal (Cu). Note, oxidation number decreased from +2 to 0.
