What should the pH of salt water be?

1 Answer
anor277
Feb 9, 2017

Of aqueous sodium chloride? #pH=7#.

Explanation:

Sodium chloride is the salt of a strong base, #NaOH#, and a strong acid, #HCl#. Because this is a strong base/strong acid pair, by definition, their counterions, #Na^+#, and #Cl^-#, do not undergo water hydrolysis. Contrast this behaviour with an aqueous solution of #"sodium fluoride"#. The #pH# of this solution is #>7#. Given that #HF(aq)#, unlike #HCl, HBr, HI#, is a WEAK ACID, how can this solution behaviour be rationalized?

Related questions
See all questions in pH
Impact of this question
4342 views around the world
You can reuse this answer
Creative Commons License