Chapter 7, Problem 3STP

Interpretation Introduction

Interpretation:

The salt which would require more energy to break the ionic bonds needs to be identified.

Concept introduction:

Ionic bond is the exchange of valence electron(s) between atoms. It creates two ions charged in opposite directions. The metal releases electrons in ionic bonds and become positively charged while the nonmetal retains electrons to become negatively charged.

Answer to Problem 3STP

${\text{BaCl}}_{\text{2}}$ needed highest energy to break the ionic bond.

Explanation of Solution

Reason for correct option:

The compound which has the highest lattice energy is required highest energy to break the ionic bonds. Lattice energy increases as the size of ion decreases and increases if the charge of the ion increases. In ${\text{BaCl}}_{\text{2}}$, the Ba carries a +2 charge and each Cl carries a $-1$ charge. Among the given compounds only Ba has highest charge. So, it is clear that ${\text{BaCl}}_{\text{2}}$ require more energy to break the ionic bond.

Conclusion

Reason for incorrect option: In option B, C and D all carry a single charge. As we know that the energy of the ionic bonds depends on the size and charge of the ion. Therefore, all three needs similar energy to break the ionic bond.