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pH describes the activity of hydronium ions (H3O+, 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:
in which a H is the activity of the solvated hydronium ion. The pH of an acidic solution is less than 7, and the pH of basic solution is greater than 7 at 25 °C, but pH values change as a function of temperature.
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© 2014 Springer-Verlag Berlin Heidelberg
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Kobayashi, K. (2014). pH. In: Amils, R., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-27833-4_1176-5
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DOI: https://doi.org/10.1007/978-3-642-27833-4_1176-5
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Publisher Name: Springer, Berlin, Heidelberg
Online ISBN: 978-3-642-27833-4
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