Calcium chloride is an ionic compound. Which of the following statements account for its ionic character?

I. Calcium has high ionization energy. II. Calcium has low ionization energy. III. Chlorine has high electron affinity. IV. Chlorine has high Ionization energy.

A. I and Il only
B. I, II and IV only
C. II, IIl and IV only
D. I, II, III and IV

Correct Answer:

Option C = II, IIl and IV only

Explanation

– CaCl2 is an ionic compound owing to the large electronegative difference between the calcium atom and chlorine atom, which is greater than 2.0. In calcium chloride, the calcium atom donates its two electrons and become cation whereas each chlorine atom gain one electron, donated by Calcium, and get a negative charge.

– Ionization energies are always positive numbers, because energy must be supplied (an endothermic energy change) to separate electrons from atoms.

– Chlorine has a high ionization energy

– Chlorine has high electron affinity among the elements. Its high affinity can be attributed to its large atomic radius, or size. Because chlorine’s outermost orbital is 3p, its electrons have a large amount of space to share with an incoming electron.