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, CrOs, F20, COz 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, Hg2Cl2,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.