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.[1][2]

Methods for purification of common solvents are available[3]

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


  1. ^ Stoye, Dieter (2000). "Solvents". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a24_437. ISBN 978-3527306732.
  2. ^ 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.
  3. ^ W. L. F. Armarego (2017). Purification of Laboratory Chemicals, 8th Edition. Elsevier. ISBN 9780128054567.