Paper 3 · June 2009 · Thermochemistry and Energetics
Which compound has the greatest numerical value of lattice energy?
ALithium iodide.
BLithium fluoride.
CSodium chloride.
DSodium bromide.
Explanation
The marking scheme gives answer B. Lattice energy increases with higher charge and smaller ionic radius. Lithium fluoride has the smallest ions (Li⁺ and F⁻), giving the highest charge density and greatest lattice energy.
ZIMSEC Chemistry Paper 3, June 2009, Q12