Classification Of Commonly Used Solvents On The Basis Of Polarity

  

Classification Of Solvents On The Basis Of Polarity

 

·        Solvent:

A substance in which solute is dissolved and forms solution is a solvent. Generally solvent is a liquid but it can also be a solid, a gas, or a supercritical fluid

·        Polarity:

Solvents are generally classified by the polarity, and considered either polar or non-polar, as indicated by the dielectric constant

Polar solvents possess significant partial charges or dipole moments. The electro negativities of the bonds between the atoms vary greatly but are measurable. Ions and other polar substances can be dissolved by a polar solvent

Non-polar solvents are liquids or solvents without a dipole moment. The solvents lack any partial positive or negative charges. Their electronegativity barely differs from one another. Since there are no opposite charges and the polar component is not attracted, non-polar solvents cannot dissolve polar com

·        Protic or Aprotic:

Protic solvents contain N- or O-H bonds. Protic liquids can participate in hydrogen bonding, a potent intermolecular force. Additionally, protons (H+) can be obtained from these O-H or N-H connections.

Aprotic solvents may contain hydrogens at some locations, but since they lack O- or N-H bonds, they are unable to form hydrogen bonds among themselves.

 

 

 

·        Commonly Used Solvents:

Solvent	Chemical polarity	Protic/aprotic	Relative polarity	Description
1.      N-Hexane	Non-Polar		0.009	n-Hexane is a very volatile aliphatic colorless odorless hydrocarbon. It is a constituent in the paraffin fraction of crude oil and natural gas and is also used as an industrial chemical and laboratory reagent.
2.      Benzene	Non-Polar		0.111	Benzene is a colorless liquid with a characteristic odor and is primarily used in the production of polystyrene. It is highly toxic and is a known carcinogen; exposure to it may cause leukemia. Used as a solvent for fats, waxes, resins, oils, inks, paints, plastics, and rubber;
3.      Toluene	Non-Polar		0.099	Toluene is a colorless, flammable, toxic liquid, insoluble in water but soluble in all common organic solvents
4.      Ethyl Acetate	Polar	Dipolar Aprotic	0.228	Ethyl acetate is a clear colorless liquid with a fruity odor, widely used solvent, especially for paints, varnishes, lacquers, cleaning mixtures, and perfumes. It is highly miscible with common organic solvents.
5.      Benzyl Alcohol	Polar	Aprotic	0.608	Benzyl alcohol is a colorless liquid with a mild pleasant aromatic odor. It is a useful solvent due to its polarity, low toxicity, and low vapor pressure.
6.      Nitromethane	Polar	Protic	0.481	Nitromethane is a colorless, oily liquid with a mild disagreeable or fruity odor. It is used as a solvent in a variety of industrial applications such as in extractions, as a reaction medium, and as a cleaning solvent
7.      Acetone	Polar	Aprotic	0.355	Acetone is a colorless mobile flammable liquid with a pleasant, somewhat fruity odor, It is readily soluble in water, ethanol, ether etc.
8.      Methanol	Polar	Protic	0.762	a light, volatile, colorless, flammable liquid with a distinctive alcoholic odor Used as solvent in the manufacture of important pharmaceutical ingredients and products such as cholesterol, streptomycin, vitamins and hormones
9.      Ethanol	polar	Protic	0.654	a clear, colorless liquid with a characteristic pleasant odor and burning taste. It is highly flammable. Ethanol is used to dissolve other chemical substances and mixes readily with water and many organic liquids
10.  DMF	Polar	Aprotic	0.386	Dimethylformamide is a clear, colorless, hygroscopic liquid with a slight amine odor. The solvent properties of DMF are particularly attractive because of the high dielectric constant, the aprotic nature of the solvent, its wide liquid range and low volatility.
11.  DMSO	Polar	Aprotic	0.444	Dimethyl Sulfoxide is a highly polar and water miscible organic liquid. It is essentially odorless, and has a low level of toxicity
12.  Water	Polar	Protic	1	A tasteless and odorless liquid at room temperature, it has the important ability to dissolve many other substances.
13.  Acetic Acid	Polar	Protic	0.648	It is an acidic, colorless liquid. its vapor is irritating to eyes and nose. It dissolves both polar and non-polar compounds