• Dr. S. R.
Bembalkar
• Professor
• Department of Chemistry
• Deogiri College
• Aurangabad
• 9421670311
Contents of Unit
Reagents:
Classification of reagents according to their action as,
Acids, Bases, Salts, oxidizing, reducing, complexing,
chelating and precipitating reagents with suitable
examples.
• Reagents
Reagent is a substance or compound that is
added to a system in order to bring about a chemical
reaction or is added to check whether a reaction occurs or
not.
In Organic Chemistry, compounds such as
Collins reagent, Fentons reagent, Grignards reagent are
frequently used. There are also Analytical reagents which
are used ot cnfirm the presence of another substances
such as Fehlings reagent, Millons reagent, Tollens reagent.
Classification of Reagents
Reagents are of following types:
1) Acidic reagents
2) Basic reagents
3) Precipitation reagents
4) Oxidizing reagents
5) Reducaing reagents
6) Complexometric reagents
1. Acidic reagents
Reagents such as HCl, H2SO4, are examples of acidic
reagents. These are used in different qualitative and
quantitative analysis.
2. Basic reagents
Reagents such as NaOH, KOH, Ba(OH)2, Ca(OH)2, NH3OH
are basic reagents. These are used in various estimations,
to adjust pH of solutioms. Also in volumetric and
gravimetric analysis.
3.Precipitation reagents
Precipitation is the chemical reaction which depends
upon ionic product and soluility product. To get
precipitation, ionic product should be greater than
solubility product. Precipitating reagents my be
organic/inorganic reagents. E.g. DMG, H2SO4, 1.10
phenantholien, etc.
4.Oxidizing reagents & 5.Reducaing reagents
Oxidizing and reducing agents are key terms used in
describing the reactants in redox reactions that transfer
electrons between reactants to form products.
Oxidizing agents or oxidant gains electrons and is reduced
in a chemical reaction. Those are also known as electron
acceptor. e.g. halogens, KNO3, HNO3, KMnO4, etc.
While Reducing agents or reductant losses electrons and is
oxidized in a chemical reaction. Those are also known as
electron donor. e.g. formic acid, sulfite compounds. e.g.
alkali earth metals, Fe, Zn, H2 etc.
OIL RIG:
Oxidation Is Loss and Reduction Is Gain of
electrons
6. Complexometric reagents
These reagents are used for the detection and
estimation of metal ions present in solution.
These are of two types: Unidentate and
polydentate . The ligand which has only one
group capable of forming a bond with the central
atom is known as unidentate ligands. e.g. X -
halogens (Cl -, Br- , I-), CN-
A ligand which has two or more groups capable of forming
bonds with the central atom are known as polydentate
ligands.
EDTA Ethylene diamine tetra acetic acid (polydentate
ligand)
CH2COOH
HOOCCH 2
::N CH2 CH2 N:
CH2COOH
HOOCCH 2
Session is open for discussion
