Question

Why are alkanes insoluble in water but soluble in organic solvents?

• A. they have high density
• B. they have weak bonds
• C. they cannot break the bonds in water
• D. all of above

Answer 1

Answer: (C)

they cannot break the bonds in water

The only new attractions between the alkane and the water molecules are Van der Waals forces. These forces do not release a sufficient amount of energy to compensate for the energy required to break the hydrogen bonds in water hence, alkane does not dissolve in water.