According to Coulomb's law, which ionic compound A-D has the smallest electrostatic potential energy (i.e., closest to zero)? The size of the anion increases in the order F

Question

According to Coulomb's law, which ionic compound A-D has the smallest electrostatic potential energy (i.e., closest to zero)? The size of the anion increases in the order F < Cl < Br < I.

Quizplus · Accepted Answer

According to Coulomb's law, the electrostatic potential energy between two ions is directly proportional to the product of their charges and inversely proportional to the distance between them. As the size of the anion increases, the distance between the cation and the anion also increases, which weakens the attraction between them and results in a smaller electrostatic potential energy. Therefore, the compound with the largest anion (i.e. smallest charge density) will have the smallest electrostatic potential energy. Among the given choices, NaI has the largest anion (I-) and thus has the smallest electrostatic potential energy.

According to Coulomb's Law, Which Ionic Compound A-D Has the Smallest