[darkSun]

Hey all,
I just got back from the NJ Science Bowl regionals, and one of the questions there involved ordering the melting points of ionic compounds. Two of the compounds were LiCl and NaCl. I said that LiCl had a higher melting point than NaCl, because its crystal lattice is higher due to Li+ having less electron shielding than Na+. This is something elementary learned in every higher school chemistry classroom.

BUT, the moderator informed us that NaCl has a higher melting point than LiCl, and even had the numbers to prove it. So now I looked everything up, and NaCl does indeed have a higher melting point than LiCl. But I also looked up their crystal lattice forces, and LiCl's is higher, as I figured. Why does this happen?

Thanks!