Question

Given the cations and anions shown here (labeled as A–D), answer the following questions. From left to right, the ions are cesium, barium, oxygen, and iodine.
1. Write the formula of the structure that would have the greatest internuclear distance between the pairs.
2. Write the formula of the structure that would have the smallest internuclear distance between the pairs.
3. Based on the internuclear distances and charges, rank the compounds in order of increasing strength of ionic interaction.

Answer 1

A : Cesium

B : Barium

C : Oxygen

D : Iodine

Internuclear distance

AD : 387 pm

A₂C : 307 pm

BC : 275 pm

BD₂ : 355 pm

AD > BD₂ > A₂C > BC

1.AD

2.BC

3.Strength of ionic bond is dependent on the charge on cation and anion and also dependent on internuclear distance.

(a) Strength of ionic bond is directly proportional to charge on cation

(b) Strength of ionic bond is directly proportional to charge on anion

(c) Strength of ionic bond is inversely proportional to internuclear distance.

Considering all these,

Strength of ionic bond : BC > A₂C > BD₂ >AD(Answer)