A solvent is a liquid substance that lets other substances get dissolved in it.
Water is a universal solvent and is least expensive and also widely. But there are other solvents preferred based on ethanol, oils, petroleum products, etc.
They find many applications in the formulation of food, drugs, cosmetics (lipsticks), and research.
Common Examples of Solvents include
- Water
- Ethanol
- Methanol
- N-propanal
- Butanol
- Ether
- Dichloromethane
- Carbon disulfide
- glycerol
- Acetone
- Carbon tetrachloride
- Cyclohexane
- Formic acid
- Toluene
- Anisole
- Pyridine
- Acetic Acid
- Hexane
- Xylene
- Trifluoroacetic acid
- Dimethyl sulfoxide
- benzene
- Nitrobenzene
- Quinoline
- Dibutyl phthalate
- Dimethylformamide
- Cyclohexane
- Anisole
- Tetrahydrofuran
- Petroleum ether
Solvents are chemical compounds that are physically liquids at room temperature. Besides these, even gases can act as solvents when required.
In science, solvents are useful for chemical analysis by titration, chromatography, spectrometry, etc.
Whereas in the industry, these solvents are mainly used for the extraction, purification, and molding of substances into different shapes.
There are different types of solvents that are routinely used.
Different types of solvents
Solvents can be classified based on their chemical nature and behavior.
A. Based upon Polarity
In general, most solvents have polarity in their internal chemistry.
This polarity is due to the concentration of opposite charges on one of the atoms or elements inside a solvent molecule.
It imparts changes to the solute molecule structure such that they get dissolved by forming ions.
When a solute is mixed in a solvent, the solvent molecules dissolve the solute by separating the solute molecules using forces like hydrogen bonding, Vanderwal forces, etc.
Examples: Sodium chloride has a NaCl molecule, which breaks into Na+ and Cl- ions when dissolved in water.
1. Polar solvents
These are solvents having a dielectric constant of more than 15. They can dissolve salts and other ionizable solutes.
Polar solvents Ex: water, alcohol. Polar solutes like salts dissolve in polar solvents.
2. Non-polar solvents.
These solvents are non-polar and have dielectric constants less than 15. They cannot form intermolecular bonds by use of hydrogen bonding, Vanderwal forces, etc. Hence they cannot dissolve polar compounds.
Nonpolar solvents Ex: Benzene, CCl4.
Fats and oils are soluble in non-polar solvents. Hence to remove lipids from an extract, petroleum ether is used in the industry.
B. Based on Chemical nature
1. Aprotic solvents (No protons).
These solvents are nonreactive and chemically inert. They neither take protons nor give protons.
Ex: benzene (C6H6). Chloroform (CHCl3).
2. Amphiprotic type
These solvents can provide and take up protons on reaction. They have a neutral pH.
Ex: Water, alcohol.
3. Protogenic type (proton+genesis = give)
These are the solvents acidic by nature. They can donate a proton and hence called “protogenic.”
Ex: HCL, H2SO4, perchloric acid.
4. Protophyllic type
These are the solvents that take up protons. They are basic by nature and are mostly alkalies.
Ex: NaOH, KOH, etc.
These and protophilic solvents can be again classified as leveling agents and differentiating agents.
A strong acid or base is a leveling agent as it can donate or accept protons to even weak base or acid, respectively.
While weak acids and weak bases cannot do so, they can only give proton to a strong base or take up a proton from a strong acid, respectively. Hence due to this differentiation, they are called differentiating agents.
C) Based on chemistry
Solvents are also classified based on their center of chemistry due to the presence of some particular elements. These unique elements in solvents bring a total change in their physical and chemical properties.
a) Inorganic solvents
Liquids without carbon in their chemistry are called inorganic solvents.
Ex: water, HCl
b) Organic solvents.
These are chemical liquids having carbon in their chemistryy
Ex: Alcohols like methanol (CH3OH), ethanol (C2H5OH), hydrocarbons like ether, acetone, Benzene.
c) Halogenated solvents
Liquids having halogens like chlorine, bromine, iodine in their chemical structure are called halogenated solvents. Halogens are elements found in the 17th group of the periodic table.
Examples of halogenated solvents are
- Carbon tetrachloride (CCl4)
- Chloroform (CHCl3)
- Bromoform (CHBr3 ; Tribromomethane)
d) Deuterated solvents
These have deuterium, a hydrogen isotope, in their molecular structure. They are preferred in experiments where hydrogen has to be avoided. For example, in nuclear magnetic spectroscopy, the solvents with hydrogen can interfere in the analysis. Hence, solvents substituted with deuterium instead of the hydrogen atom are preferred.
Their examples include Deuterated form of water (D2O), methanol (CD3OD), acetic acid (CD3COOD), trifluoroacetic acid (CF3COOD), etc.
Based on their behavior and properties, solvents are selected for purposes like acid-base titration, complexometry, extraction procedures, solubilization, chromatography, spectrophotometry, etc.
The above nature seems highly specific. Because, sugar (C12H22O12) molecules are organic by nature due to the presence of carbon in it.
But interestingly, sugar is insoluble in organic solvents like benzene. This is because sugar molecules have polarity and require polar solvents to dissolve.
Hence we see sugar dissolves well in plain water, which is inorganic but having polarity.
So among the types of solvents available, to dissolve a solute, one should consider both chemistry and polarity.
D) Based on Physical property
a) Volatile type: These are the volatile liquids and evaporate as gas at around room temperature due to low boiling points. They can be stored in ambered colored containers with tight closure. But, once they are kept open, the liquid starts evaporating and over a period of time, like in hours, the container gets empty.
If the liquid has an aroma, it can be felt all over the room if the lid is kept open.
Examples: Diethyl ether (B.P= 34.5 degree centigrade)
b) Non-Volatile type: Most of the solvents come under this category. They have high boiling points and hence are stable at room temperature. They get evaporated when heated to higher temperatures depending on their boiling points.
Examples: Water (B.P= 100 degrees), ethanol (B.P=78 degrees).
c) High-density type: These liquids have high density and can be called as heavy liquids. Due to this, their weight per volume is higher than those with low density.
Examples: Chloroform has a density of 1.49 g/cm³.
d) Low-density type: These liquids have low density due to which their weight per volume is lower.
Examples: petroleum ether has a density of 0.64 g/cm3.
Examples of solvents used at home
From the above list you might find that few of them could be found at home on regular basis. The solvents at home are
- Water
I need to use touch up paint on my fairly new car. I purchased from the dealarship touch up paint. But i need to clean the scratch before applying. What could I use that would be probably found in my household?
love it
Thanks
Thank you for getting back to me. Soap and water don’t work. I wish it was that easy. I have to find someone who can figure out what it is.
Interesting information! I took three chemistry courses in college about 35 years ago, but the data you have is a little advanced for me. Would you happen to know where I could go in the NY Metro Area to get the chemical samples of what I spilled on my hands identified so I can get it safely removed. The container did not have a label on it. Thank you. Tom
Hi Tom, washing hands immediately with soap and water is the best option.
Thanks!
Really helped me with a science essay
This was a great way of sending information! It really helped me study on my test! Nice work!
very educative. I would like to have more
Good site!!
kindly advise the best solvents for removal of bitumen( protection coating) from CS pipe weld fittings which are already fabricated with piping.
please advise what procedure makes the better removal of bitumen from the fabricated piping
either high-pressure water jets by using a rotating nozzle or dip method with recommended solvents
what are all the good resulted solvents
your valuable suggestions are highly appreciated