Science

Math

Humanities

... and beyond

Socratic Meta
Featured Answers

Topics

What does a pH scale measure?

1 Answer

Sep 25, 2016

It measures $[H_{3} O^{+}]$ $[H_3O^+]$ , i.e. hydronium ion concentration.

Explanation:

And $p H = - {log}_{10} [H_{3} O^{+}]$ $pH=-log_10[H_3O^+]$

$[H_{3} O^{+}]$ $[H_3O^+]$ derives from water's autoprotolysis:

$2 H_{2} O (l) ⇌ H_{3} O^{+} + H O^{-}$ $2H_2O(l) rightleftharpoonsH_3O^+ + HO^-$

At $298 K$ $298K$ , $K_{a} = 10^{- 14}$ $K_a=10^-14$ , and thus $p H + p O H = 14$ $pH+pOH=14$

Related questions

See all questions in pH calculations

Impact of this question

1796 views around the world

You can reuse this answer
Creative Commons License