Which listing of ionic compounds is in order of increasing melting point? A) NaF

Question

Which listing of ionic compounds is in order of increasing melting point? A) NaF < MgF₂ < AlF₃ B) MgF₂ < NaF < AlF₃ C) AlF₃ < MgF₂ < NaF D) AlF₃ < NaF < MgF₂ E) NaF < AlF₃ < MgF₂

Quizplus · Accepted Answer

The melting point of ionic compounds increases with increasing lattice energy. Lattice energy increases with increasing charge of the ions and decreasing size of the ions. In this case, the ions are all the same size, so the melting point increases with increasing charge of the ions. The charge of the ions increases from Na+ to Mg2+ to Al3+, so the melting point increases in the order NaF < MgF2 < AlF3.

Which Listing of Ionic Compounds Is in Order of Increasing