Some molecular compounds, such as HCl, ionize completely in solution. Some molecular compounds such as HC2H3O2 do not ionize completely when they dissolve in water. Which explains their solution properties?

There are two types of electrolytes: the strong and the weak electrolytes. Strong electrolytes are those which dissociates completely in solutions while weak electrolytes are those that do not. HCl is a strong electrolyte since it is a strong acid while HC2H3O2 is a weak one as it is a weak acid as well.