Final answer:
The compounds with higher ionic charges and smaller ionic radii generally have larger lattice energies. As such, Na₂O, BaS, and BaS (in different comparisons) have larger lattice energies than their respective counterparts.
The correct answer is options (a) K₂O or Na₂O.
Step-by-step explanation:
The lattice energy of an ionic compound is the amount of energy released when the ions in the gas phase come together to form the solid lattice. Generally, lattice energy increases with the charge of the ions and decreases with the size of the ions. Here are the explanations for the provided pairs:
- (a) Na₂O has a larger lattice energy than K₂O because Na+ has a smaller ionic radius than K+, leading to stronger electrostatic attraction between Na+ and O²⁻.
- (b) BaS has a larger lattice energy than K₂S because Ba²+ has a larger charge than K+.
- (c) BaS has a larger lattice energy than KCl because both Ba²+ and S²- have larger charges than K+ and Cl-.
- (d) BaS has a larger lattice energy than BaCl₂ because S²- has a larger charge than Cl-.
These choices are based on the general rules that ionic compounds with higher charges on their ions and smaller ionic radii will have larger lattice energies due to stronger electrostatic attraction between the ions.
The correct answer is options (a) K₂O or Na₂O.