Let's compare the two ionic compounds, NaCl and CaCl₂, in terms of electrostatic attraction, strength of the ionic bond, and melting point.
### (i) Electrostatic Attraction
The electrostatic attraction between ions in an ionic compound depends on the charges of the ions and the distance between them.
- NaCl: In this compound, the ions are Na⁺ (sodium ion with a +1 charge) and Cl⁻ (chloride ion with a -1 charge).
- CaCl₂: In this compound, the ions are Ca²⁺ (calcium ion with a +2 charge) and Cl⁻ (chloride ion with a -1 charge).
Since Ca²⁺ carries a double positive charge as opposed to Na⁺ with a single positive charge, the electrostatic attraction between Ca²⁺ and Cl⁻ ions is stronger than the attraction between Na⁺ and Cl⁻ ions. Therefore, the electrostatic attraction in CaCl₂ is greater than in NaCl.
Thus, the statement "electrostatic attraction NaCl > CaCl₂" is incorrect.
### (ii) Strength of the Ionic Bond
The strength of an ionic bond is proportional to the product of the charges of the ions involved.
- NaCl: The product of the charges here is [tex]\(+1 \times -1 = -1\)[/tex].
- CaCl₂: The product of the charges here is [tex]\(+2 \times -1 = -2\)[/tex].
Since the product of the charges (in absolute terms) is greater for CaCl₂, the strength of the ionic bond in CaCl₂ is stronger than in NaCl.
Thus, the strength of the ionic bond is greater in CaCl₂ than in NaCl.
### (iii) Melting Point
Melting point correlates with the electrostatic attraction between ions. Stronger electrostatic attraction leads to a higher melting point because more energy is required to break the bonds holding the ions together.
- NaCl: This compound has weaker electrostatic attraction compared to CaCl₂.
- CaCl₂: This compound has stronger electrostatic attraction due to the higher charge on the Ca²⁺ ion.
Because CaCl₂ has stronger ionic bonds and therefore stronger electrostatic attraction, it also has a higher melting point than NaCl.
Thus, CaCl₂ has a higher melting point than NaCl.
### Summary
1. Electrostatic Attraction: NaCl < CaCl₂ (statement that NaCl > CaCl₂ is incorrect)
2. Strength of Ionic Bond: CaCl₂ > NaCl
3. Melting Point: CaCl₂ > NaCl
