Question

In which are the ionic solids ranked in order of increasing melting point?

(A) KBr < NaCl < NaF < MgO
(B) NaF < NaCl < MgO < KBr
(C) KBr < NaCl < MgO < NaF
(D) MgO < NaF < KBr < NaCl

Answer 1

Answer:A

Step-by-step explanation:

The melting points of solids depend in the relative sizes of ions in the ionic lattice. The smaller the relative sizes of the ions, the higher the lattice energy and the stronger the lattice hence higher melting point. Comparing relative ionic sizes, fluoride ion is lesser in size than chloride ion hence NaF has a higher melting point than NaCl.