Answer:

Introduction:
Boiling point is directly proportional to the strength of intermolecular forces between the molecules in a solution. The stronger the intermolecular forces, the higher the boiling point.

Comparison of boiling points:
1. 1M NaCl: NaCl is an ionic compound that dissociates into Na+ and Cl- ions in water. The intermolecular forces between these ions and water molecules are relatively weak. Hence, the boiling point of 1M NaCl is relatively low.
2. 1M CaCl2: CaCl2 is also an ionic compound that dissociates into Ca2+ and Cl- ions in water. However, it has more ions per unit volume than NaCl. Therefore, the intermolecular forces between these ions and water molecules are stronger, resulting in a higher boiling point than NaCl.
3. 1M AlF3: AlF3 is a covalent compound that does not dissociate into ions in water. Instead, it forms hydrogen bonds with water molecules. Hydrogen bonds are relatively strong intermolecular forces. Hence, the boiling point of 1M AlF3 is higher than both NaCl and CaCl2.
4. 1M Al2(SO4)3: Al2(SO4)3 is also a covalent compound that forms hydrogen bonds with water molecules. However, it has more ions per unit volume than AlF3. Therefore, the intermolecular forces between these ions and water molecules are stronger, resulting in the highest boiling point among the given options.

Conclusion:
In summary, the order of boiling points for the given solutions is:
1M NaCl < 1m="" cacl2="" />< 1m="" alf3="" />< 1m="" al2(so4)3.="" 1m="" />

The boiling and melting points are a function of the INTERMOLECULAR bonds more so that the internal bonds. I think D is correct answer