Question

Select the correct order of lattice energy.

• A. $LiF<LiBr<LiI$
• B. $LiCl>LiBr>LiI$
• C. $LiCl>NaCl>KCl$
• D. $BeC{O}_3<MgC{O}_3<SrC{O}_3<BaC{O}_3$

Answer 1

Answer: (B), (C)

The correct options are
B $LiCl>LiBr>LiI$
C $LiCl>NaCl>KCl$

The lattice energy decreases in the order $LiCl>LiBr>LiI$.

As the size of the anion increases from chloride to iodide, the lattice energy decreases.
The lattice energy decreases in the order $LiCl>NaCl>KCl$.

As the size of the cation increases from lithium to potassium, the lattice energy decreases.