Explain redox reactions based on electron transfer.

In a redox reaction if one species loses electrons it’s considered to be undergoing oxidation reaction and acts as oxidizing agent or oxidant, and for species who accepts electrons is said to undergo reduction and behave as reductant.

For example Zinc and HCl reaction

Zn + 2HCl → ZnCl2 + H2

zinc loses electrons to the electronegative atom Cl with the reaction for oxidation and reduction as follows:

Oxidation: Zn→Zn2+ + 2e-

Reduction: 2H+ + 2e- →H2

Thus the transfer of electrons causes the redox reaction to occur.