Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso


  • Kensei Kobayashi
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_1176-5



pH describes the activity of hydronium ions (H 3O +, or more precisely the hydrated form of the proton H + in solution) in aqueous solution. pH characterizes the acidity or basicity of aqueous solutions. It is formally defined by the relation:
$$ \mathrm{p}\mathrm{H}=-{ \log}_{10}{a}_{\mathrm{H}} $$


Aqueous Solution Acidic Solution Bioorganic Chemistry Basic Solution Concentration Index 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in to check access.

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Yokohama National UniversityYokohamaJapan