What is the difference solvent between hydrochloric acid and acetic acid?

The difference between hydrochloric acid and acetic acid is water.

Generally speaking, the solubility of substances in inert solvents varies greatly, so inert solvents are different solvents. Water cannot flatten hydrochloric acid and acetic acid, because the alkalinity of water is too weak for acetic acid, and the proton transfer reaction is very incomplete.

HAc+H2OH3O++Ac

There are a lot of acetic acid molecules in the solution, but few hydrated protons. Because hydrochloric acid and acetic acid have different reactions in solvent water, they show different acid strengths. This effect of distinguishing the strength of acid (base) is called polymerization effect. Solvents with polymerization are called identification solvents. For hydrochloric acid and acetic acid, water is a good solvent to distinguish.