Acidic Salt
A salt whose aqueous solution has a pH below 7, or one that still contains replaceable hydrogen.
Unit
Dimensionless
In depth
The term covers two distinct cases: salts of a strong acid with a weak base, which are acidic through cation hydrolysis, and partially neutralised polyprotic acids, which retain an ionisable proton. Highly charged hydrated metal cations are acidic for the same reason.
Examples in the real world
Ammonium chloride at pH 5; sodium hydrogensulfate, which still carries an acidic proton.