|Class 11 Chemistry Redox Reactions||Rules to assign and calculate oxidation number|
Rules to assign and calculate oxidation number
Oxidation: It is defined as increase in oxidation number of an element.
Mg + H2 --> Mg2+ H2
Magnesium Hydrogen MagnesiumHydride
In this, Magnesium oxidation number is increased from 0 to +2.Therefore, oxidation occurs.
Reduction: It is defined as decrease in oxidation number of an element.
Fe3+ + e- --> Fe2+
Ferric Ion Ferrous Ion
In this oxidation number of iron is reduced .Therefore, reduction occurs.
Redox reaction in terms of oxidation number
In this, Zinc is undergoing oxidation and act as reducing agent whereas Hydrogen is undergoing reduction and act as an oxidizing agent.
Zn0 + H+Cl- --> Zn2+ + 0H2
Zinc HydrogenChloride Zinc Chloride Hydrogen Gas
Q: Find the oxidation number of N in NO32- ?
Q: Find the oxidation number of S in H2SO4 ?