Liquid ammonia is a polar solvent, meaning that its molecules have a positive end and a negative end. This polarity allows it to dissolve ionic compounds, such as sodium chloride, into its constituent ions. However, liquid ammonia does not conduct electricity, which is the defining characteristic of an electrolyte. This is because the ions in liquid ammonia are not free to move, as they are surrounded by polar solvent molecules.

In contrast, aqueous ammonia is a good electrolyte. This is because water is also a polar solvent, but it is more effective at solvating ions than liquid ammonia. This means that the ions in aqueous ammonia are more likely to be free to move, allowing the solution to conduct electricity.

The difference in the conductivity of liquid ammonia and aqueous ammonia can be explained by the difference in the strength of the hydrogen bonding between the solvent molecules. Hydrogen bonding is a type of intermolecular force that occurs when a hydrogen atom is bonded to a highly electronegative atom, such as nitrogen or oxygen. In liquid ammonia, the hydrogen bonding between the ammonia molecules is stronger than the hydrogen bonding between the ammonia molecules and the ions. This means that the ions are more strongly solvated in liquid ammonia, and are therefore less likely to be free to move.

In contrast, the hydrogen bonding between the water molecules in aqueous ammonia is weaker than the hydrogen bonding between the water molecules and the ions. This means that the ions are more weakly solvated in aqueous ammonia, and are therefore more likely to be free to move.

The difference in the strength of the hydrogen bonding between the solvent molecules also explains the difference in the boiling points of liquid ammonia and aqueous ammonia. Liquid ammonia has a boiling point of -33.4 °C, while aqueous ammonia has a boiling point of 100 °C. The stronger hydrogen bonding between the ammonia molecules in liquid ammonia means that more energy is required to break the bonds and vaporize the liquid.