Which of the following pairs of ions is arranged so that the ion with the smaller charge density is listed first? A) K⁺, Rb⁺ B) Cl^¯, K⁺ C) Cl^¯, Br^¯ D) Ca²⁺, Ba²⁺ E) None of these pairs are arranged in this way.

Question

Quizplus · Accepted Answer

In an ion pair, the charge density increases with the magnitude of the charge and decreases with the size of the ion. Therefore, in the pair Cl¯ and K+, the Cl¯ ion has a larger charge density than K+. Similarly, in the pair Cl¯ and Br¯, the Cl¯ ion has a smaller size and larger charge density than Br¯. Therefore, the pair Cl¯ and K+ in option B is arranged so that the ion with smaller charge density (K+) is listed first.

Which of the Following Pairs of Ions Is Arranged So