IEVref:114-01-21ID:
Language:enStatus: Standard
Term: pH
Synonym1:
Synonym2:
Synonym3:
Symbol:
Definition: number quantifying the acidic or the alkaline character of a solution, equal to the negative of the decimal logarithm of ion activity aH+ of the hydrogen cation H+

pH = −10 lg aH+

Note 1 to entry: At about 25 °C aqueous solutions with:

  • pH < 7 are acidic;
  • pH = 7 are neutral;
  • pH > 7 are alkaline.

At temperatures far from 25 °C the pH of a neutral solution differs significantly from 7.

Note 2 to entry: For more details, see ISO 80000-9:2009, Annex C.

Note 3 to entry: This entry was numbered 111-15-37 in IEC 60050-111:1996. It has been modified.


Publication date:2014-03
Source
Replaces:
Internal notes:2017-08-28: Removed unnecessary <p> tags. LMO
CO remarks:
TC/SC remarks:
VT remarks:
Domain1:
Domain2:
Domain3:
Domain4:
Domain5: