Four binary ionic solids are listed below together with the ionic radii of their…
CHEMISTRY · Multi-part · ISC · Chemistry · Chemical Bonding and Molecular Structure · Chemical Bonding and Molecular Structure
Problem
Four binary ionic solids are listed below together with the ionic radii of their constituent ions.
Ionic radii (pm):
• Cs⁺ 174, Na⁺ 102, Mg²⁺ 72, Al³⁺ 53
• F⁻ 133, Cl⁻ 181, O²⁻ 140, N³⁻ 146
Solids to be analyzed:
(a) Identify the solid among the four whose cation–anion separation is expected to be the smallest. Explain your reasoning using the numerical data provided.
(b) Rank the four solids from greatest-magnitude lattice energy (most exothermic) to least-magnitude lattice energy (least exothermic).
(c) Justify the ranking in part (b) by discussing how both the magnitude of ionic charge and the inter-ionic distance contribute to the relative lattice energies for these solids.