In chemistry, a protic solvent is a solvent that has a hydrogen atom bound to an oxygen (as in a hydroxyl group −OH), a nitrogen (as in an amine group −NH2 or −NH−), or fluoride (as in hydrogen fluoride). In general terms, any solvent that contains a labile H+ is called a protic solvent. The molecules of such solvents readily donate protons (H+) to solutes, often via hydrogen bonding. Water is the most common protic solvent. Conversely, polar aprotic solvents cannot donate protons but still have the ability to dissolve many salts.
Methods for purification of common solvents are available
| Solvent | Chemical formula | Boiling point | Dielectric constant | Density | Dipole moment (D) |
|---|---|---|---|---|---|
| Polar protic solvents | |||||
| formic acid | HCO2H | 101 °C | 58 | 1.21 g/mL | 1.41 D |
| n-butanol | CH3CH2CH2CH2OH | 118 °C | 18 | 0.810 g/mL | 1.63 D |
| isopropanol (IPA) | (CH3)2CH(OH) | 82 °C | 18 | 0.785 g/mL | 1.66 D |
| nitromethane [note 2] | CH3NO2 | 101°C | 35.87 | 1.1371 g/mL | 3.56 D |
| ethanol (EtOH) | CH3CH2OH | 79 °C | 24.55 | 0.789 g/mL | 1.69 D |
| methanol (MeOH) | CH3OH | 65 °C | 33 | 0.791 g/mL | 1.70 D |
| Acetic acid (AcOH) | CH3CO2H | 118 °C | 6.2 | 1.049 g/mL | 1.74 D |
| Water | H2O | 100 °C | 80 | 1.000 g/mL | 1.85 D |
See also
References
Stoye, Dieter (2000). "Solvents". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a24_437. ISBN 3527306730. 3527306730 ↩
John R. Rumble (ed.). "Laboratory Solvent Solvents and Other Liquid Reagents". CRC Handbook of Chemistry and Physics, 102nd Edition (Internet Version 2021). Boca Raton, FL, USA: CRC Press/Taylor & Francis. ↩
W. L. F. Armarego (2017). Purification of Laboratory Chemicals, 8th Edition. Elsevier. ISBN 9780128054567. 9780128054567 ↩