PrepGo

AP Chemistry Practice Quiz: Structure of Ionic Solids

Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026

Test your understanding with short quizzes. This quiz has 7 questions to check your progress.

Question 1 of 7

Which statement best describes the fundamental arrangement of ions within an ionic crystal lattice?

All Questions (7)

Which statement best describes the fundamental arrangement of ions within an ionic crystal lattice?

A) Positive and negative ions are arranged in an alternating, systematic pattern.

B) All positive ions are clustered in the center, surrounded by negative ions.

C) Ions are randomly distributed throughout the solid.

D) Layers of cations are separated by layers of anions.

Correct Answer: A

Ions in an ionic crystal are arranged in a systematic, 3D array that maximizes the attractive forces between oppositely charged ions and minimizes the repulsive forces between like-charged ions. This is achieved through an alternating pattern of cations and anions.

The formation of a stable, three-dimensional ionic lattice is a direct consequence of which physical law?

A) The Law of Conservation of Mass

B) Newton's Law of Universal Gravitation

C) Coulomb's Law

D) The Ideal Gas Law

Correct Answer: C

Coulomb's law describes the electrostatic forces of attraction between opposite charges and repulsion between like charges. The ionic lattice structure is the arrangement that best satisfies these forces, maximizing attraction and minimizing repulsion, leading to the most stable, lowest-energy state.

A student is asked to draw a particulate model of an ionic solid. Which of the following features in the model would be inconsistent with the principles of ionic crystal structure?

A) A cation is shown surrounded by several anions.

B) The ions are arranged in a repeating, geometric pattern.

C) Two large anions are shown in direct contact with each other.

D) The number of positive charges equals the number of negative charges in the overall model.

Correct Answer: C

The structure of an ionic solid is organized to minimize repulsions between ions with the same charge. Placing two anions (which are both negatively charged) in direct contact would maximize electrostatic repulsion, which is energetically unfavorable and not representative of a stable ionic lattice.

The primary energetic driving force for the specific, ordered arrangement of ions in a crystal lattice is to:

A) maximize the potential energy of the system.

B) minimize the overall electrostatic potential energy.

C) ensure that all ions are equidistant from one another.

D) allow for the free movement of ions within the solid.

Correct Answer: B

Systems in nature tend toward the lowest possible energy state. For an ionic solid, this is achieved by arranging the ions to maximize the strong attractions between opposite charges and minimize the repulsions between like charges. This arrangement results in the minimum possible overall electrostatic potential energy for the system.

Based on Coulomb's Law and the properties of the constituent ions, how would the net attractive forces in a crystal of calcium sulfide (CaS), composed of Ca²⁺ and S²⁻ ions, compare to those in potassium chloride (KCl), composed of K⁺ and Cl⁻ ions, assuming similar interionic distances?

A) The forces in CaS would be stronger because the magnitude of the charges is greater.

B) The forces in KCl would be stronger because the ions are in a different group on the periodic table.

C) The forces would be approximately the same because the lattice structure is similar.

D) The forces in CaS would be weaker because of increased electron-electron repulsion in the ions.

Correct Answer: A

Coulomb's Law states that the electrostatic force is directly proportional to the product of the magnitudes of the charges (F ∝ q1*q2). For CaS, the product of the charge magnitudes is |(+2) * (-2)| = 4. For KCl, the product is |(+1) * (-1)| = 1. Therefore, the electrostatic attractions are significantly stronger in the CaS lattice.

The principle that an ionic lattice is arranged to minimize repulsions is best illustrated by which observation in a particulate model?

A) Each cation is positioned as close as possible to an anion.

B) Each cation is positioned as far as possible from other cations.

C) The overall solid has no net electrical charge.

D) The ions are locked in fixed positions.

Correct Answer: B

Minimizing repulsions specifically refers to the forces between like-charged ions. In a stable lattice, cations (+ charge) are arranged to be as far apart from other cations as the geometry allows, and likewise for anions (- charge), to reduce the energetically unfavorable repulsive forces.

Which statement most accurately synthesizes the principles governing the structure of an ionic solid?

A) An ionic solid is a 3D array of ions whose structure is determined solely by the relative sizes of the ions.

B) An ionic solid consists of a systematic 3D lattice where the placement of ions is governed by Coulomb's law to create the most energetically stable arrangement.

C) An ionic solid is a crystalline structure where attractions and repulsions are perfectly balanced, resulting in zero net force on any ion.

D) An ionic solid has a random particulate structure that ensures overall charge neutrality.

Correct Answer: B

This statement correctly combines all the key concepts: the structure is a systematic 3D lattice, the governing principle is Coulomb's law, and the goal is to maximize attractions and minimize repulsions to achieve the lowest energy (most stable) state.