Question

How do we determine the acidity of a salt?

Answer 1

How else but by experiment and measurement?

Explanation:

So dissolve the salt, and measure the `pH`. The salts of strong acids (i.e. lower hydrogen halides, nitric, sulfuric acids) generally give `pH` neutral solutions.

The salts of weaker acids, e.g. sodium fluoride, give basic solutions. But `pH` measurement is made first so that we can work out what is going on in solution.