Why is it not correct/precise to say "a molecule of salt?"

It is not correct to say " a molecule of salt " because salt is a compound.

Explanation:

As we know a molecular bond is present in each molecule. Salt (NaCl) is considered as a compound because it is made up of two types of elements that are sodium as well as chlorine. On the other hand it is not considered as a molecule as it is not holding an ionic bond. As a result we can name it as an ionic compound. Hence it is not considered as a molecule of salt.