NEET Chemistry Notes Redox Reactions-Concepts of Oxidation and Reduction

NEET Chemistry Notes Redox Reactions-Concepts of Oxidation and Reduction

Concepts of Oxidation and Reduction

Concepts of Oxidation and Reduction

Loss of electron by an atom is called oxidation or de-electronation while gain of electron by an atom is called reduction or electronation.

Oxidants or oxidising agents These are the substances which

• oxidise other,
•  get reduced,
•  gain electrons (i.e. their oxidation number decreases during a reaction)

Reductants or reducing agents These are the substances which

• reduce others,
•  get oxidised,
• lose electrons (i.e. their oxidation number increases during a reaction)

Some Important Oxidants

Some important oxidants used in oxidation are given below:

•  Molecules of most electronegative elements such as 0₂,0₃, halogens.
•  Oxides of metals and non-metals such as as MgO, CaO, CrO_s, F₂0, CO_z etc.
•  The compounds having either of an element in their highest oxidation state such as K₂Cr₂0₇, KMn0₄, HCl0₄, H₂S0₄, HN0₃, FeCl₃, HgCl₂, KCl0₃ etc.
• Permanganate ion acts as strong oxidising agent and in acidic medium it always produces 5 electrons per formula unit irrespective of the reducing agent.

Some Important Reductants

Some important reductants used in reduction are given below:

• All metals such as Na, Al, Zn etc., and some non-metals, e.g. C, S, P, H₂ etc.
•  Metallic hydrides such as NaH, LiH, KH, CaH₂ and halogen acids such as HCl, HBr, HI.
•  The compounds having either of an element in their lowest oxidation state such as H₂C₂0₄, FeS0₄,  Hg_2Cl2,Cu₂0, SnCl₂

Equivalent weights of Oxidising Agent (OA) or Reducing Agent (RA)

Equivalent weight of oxidising agent or reducing agent may be formulated as,

H₂0₂ is both oxidising and reducing agent but its equivalent weight as either oxidising or reducing agents are the same, i.e. 17.

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