Which compound is likely to have a lower melting/boiling point?Hydrochloric acid or Potassium sulfate? Justify.

Now I know that hydrochloric acid has the lower melting and boiling point because it is covalent and potassium sulfate has an ion-ion force acting on it.

But the part where I am confused is how is an acid covalent? Isn't it suppose to be ionic due to the H+ ion. So my final question is what are the intermolecular forces acting on each of the compounds?

HCl is a polar covalent compound while K2SO4 is an ionic compound. Most ionic compounds have high melting/boiling points.