# The lattice energy for sodium iodide is 700 kJ/mol, while that for calcium sulfide is 2775 kJ/mol. Which of these salts do you predict has the higher melting point?

Jan 11, 2017

Melting something requires that you break its lattice structure and let it move somewhat freely as a liquid. Thus, the harder it is to break the lattice structure, the harder it is to melt the substance and higher the melting point.

As a result, the one with a higher lattice energy has the higher melting point.