16. Consider the dissociation reaction of the acid HF. HF(aq) ⇌ Why is △S negative? (A) Each HF molecule produces two ions when it dissociates. ; (B) The ions are hydrated.; (C) The reaction is expected to be exothermic, and △S thus should be negative. ; (D) The reaction is expected to be endothermic, and △S thus should be negative. ; (E) none of these.