Question

Rank the following salts in order of increasing lattice energy: lithium chloride, calcium oxide, aluminum oxide, sodium chloride, barium oxide.

Please explain! Thank you.

Answer 1

The salts are ranked based on ionic charges and sizes, with sodium chloride having the lowest lattice energy and aluminum oxide the highest.

Step-by-step explanation:

To rank the salts lithium chloride (LiCl), calcium oxide (CaO), aluminum oxide (Al2O3), sodium chloride (NaCl), and barium oxide (BaO) in order of increasing lattice energy, we need to consider the charges of the ions and their sizes, as lattice energy is directly proportional to the product of the ionic charges and inversely proportional to the internuclear distance. Here is how they can be ranked based on these factors:

LiCl (Li+ and Cl−): Low charge, relatively small ions.

NaCl (Na+ and Cl−): Similar to LiCl but Na+ has a larger ionic radius than Li+, which results in lower lattice energy compared to LiCl.

CaO (Ca2+ and O2−): Higher charges on ions, but smaller than Ba2+ of BaO.

BaO (Ba2+ and O2−): Same charge as CaO but larger ions because Ba2+ is larger than Ca2+.

Al2O3 (Al3+ and O2−): Highest charges and small ionic sizes lead to the highest lattice energy.

Therefore, the order of increasing lattice energy is NaCl < LiCl < CaO < BaO < Al2O3.

Answer 2

barium oxide < calcium oxide< sodium chloride < lithium chloride < aluminum oxide

Step-by-step explanation:

The lattice energy can be defined as the change in internal energy accompanying the formation of a single mole of an ionic solid from its gaseous constituents at 0 K.

The lattice energy depends on the relative sizes of cations and anions in the compound. The smaller the cations and anions, the greater the lattice energy.

If we look as the proposed order of increasing lattice energy of the compounds; barium oxide < calcium oxide< sodium chloride < lithium chloride < aluminum oxide, we will notice that it follows the order of decrease in the sizes of both the ions, Ba^2+ > Ca^2+ > Na+ >Li+ > Al^3+.

The smaller the ions involved, the greater the lattice energy as one can see from the order listed above.