Origin of hydrogen ion
Examples from the Web for hydrogen ion
It is very likely that in aqueous acids, a large proportion, at least, of the hydrogen-ion is similarly combined with water.
That is, different concentrations of hydrogen-ion or of hydroxide-ion are required to change their colors.
The hydrogen-ion will very decidedly reduce the concentration of the acetate-ion, acetic acid being a weak acid (table, p. 104).