The melting point and boiling point of ethanol are indeed lower than that of sodium chloride. This is because ethanol is a covalent compound, while sodium chloride is an ionic compound. Covalent compounds have weaker intermolecular forces than ionic compounds, which means less energy is required to break the bonds holding the molecules together. Therefore, covalent compounds tend to have lower melting and boiling points than ionic compounds.However, the reason given in (R) is not entirely correct. The forces of attraction between the molecules of ionic compounds are indeed very strong, but this is not the only reason why they have high melting and boiling points. The main reason why ionic compounds have high melting and boiling points is that they form a crystalline lattice structure, in which each ion is attracted to several oppositely charged ions in all directions, forming a three-dimensional network of strong electrostatic attractions. Breaking these strong electrostatic attractions requires a large amount of energy, which is why ionic compounds have high melting and boiling points.