Water is a polar solvent. The water molecules can form hydrogen bonds with the solute molecules. Due to the polar nature of the water molecules, the ionic compounds can dissolve in water.

The ionic compounds have very strong intermolecular interactions. The polar nature of the water molecules can overcome the strong ionic interactions with the weak dipole interactions. As a result, the ionic compounds become soluble in water.

The solubility of organic compounds depends upon the presence of an electronegative atom, such as an oxygen or nitrogen atom, in their structure. The carbon atoms in the chain should be less than or equal to five carbons.

Diethyl ether

It has four carbon atoms in its structure. It also consists of an electronegative oxygen atom thatcan form hydrogen bonds with water. As a result, diethyl ether is soluble in water.

b. The given compound is pentane.

Pentane

It consists of carbon and hydrogen atoms only. This compound is non-polar in nature. As a result, it is insoluble in water.

c. The given compound is tributylamine.

Tributylamine

It consists of an electronegative nitrogen atom, which is capable of forming hydrogen bonds with water molecules. It also consists of the alkyl groups attached to the nitrogen atom that are more than five carbon chains.

As a result, this compound becomes insoluble in water.