How does increasing the charges of ions in an ionic lattice affect lattice energy?

How does increasing the charges of ions in an ionic lattice affect lattice energy?

• A. Decreases
• B. Has No Effect
• C. Increases
• D. Affects Only Anions

Answer: (C)

Lattice energy reflects how strongly the ions attract each other in an ionic solid. It scales with the electrostatic interaction between the ions, which, in simple terms, is proportional to the product of their charges divided by the distance between them (E ∝ q1 q2 / r). If you increase the charges on the ions, the product q1 q2 becomes larger in magnitude, so more energy is required to separate the ions and break the lattice. That’s why moving from ions with a single positive or negative charge to ions with higher charges (for example, from 1+ and 1− to 2+ and 2−) leads to a noticeably larger lattice energy. The spacing between ions doesn’t change enough to counteract this effect, so the stronger electrostatic attraction dominates. Importantly, it’s the charges on both ions that matter—the increase on either ion increases the product and raises the lattice energy, not just effects limited to the anion.

Lattice energy reflects how strongly the ions attract each other in an ionic solid. It scales with the electrostatic interaction between the ions, which, in simple terms, is proportional to the product of their charges divided by the distance between them (E ∝ q1 q2 / r). If you increase the charges on the ions, the product q1 q2 becomes larger in magnitude, so more energy is required to separate the ions and break the lattice.

That’s why moving from ions with a single positive or negative charge to ions with higher charges (for example, from 1+ and 1− to 2+ and 2−) leads to a noticeably larger lattice energy. The spacing between ions doesn’t change enough to counteract this effect, so the stronger electrostatic attraction dominates. Importantly, it’s the charges on both ions that matter—the increase on either ion increases the product and raises the lattice energy, not just effects limited to the anion.