From the following list of aqueous solutions and water, select the one with the lowest freezing point.

(A) 1.0 m LiClO4
(B) 1.5 m CH3OH, methyl alcohol
(C) 0.75 m (NH4 )3PO4
(D) pure water
(E) 1.0 m CaSO4

the correct answer is b. a strong acid completely dissociates to its ions when dissolved in water. completely dissociates to and ions. a is incorrect because does not fully ionize to and ions and some remain as the compound . c and d are incorrect because, and do not fall into the category of bronsted lowry acids. a bronsted lowry acid is a proton donor and since both molecules do not have a proton to donate they are not bronsted lowry acids. likewise,   if we use the lewis acid definition, they cannot be acids. a lewis acid is an electron pair acceptor. both and have a complete octet so can not accept any electrons which disqualifies them as acids.