Choose the correct answer for each question.

1. In liquid propanone (acetone) the forces between the molecules are
   

   1.   ?    covalent only
   2.   ?    van der Waals only
   3.   ?    van der Waals and dipole attractions
   4.   ?    van der Waals and covalent
   5.   ?    Van der Waals, dipole attractions and hydrogen bonding

2. In which one of the following are the van der Waals forces weakest in the liquid state?
   

   1.   ?    Tetrachloromethane
   2.   ?    Argon
   3.   ?    Chlorine
   4.   ?    Hydrogen

3. In ethanol C₂H₅OH, the attractions between neighbouring molecules are
   

   1.   ?    covalent bonds and van der Waals' forces only
   2.   ?    covalent bonds and hydrogen bonds only
   3.   ?    hydrogen bonds and van der Waals' forces only
   4.   ?    covalent bonds only

4. The forces of attraction between neighbouring S₈ rings in rhombic sulphur are
   

   1.   ?    covalent.
   2.   ?    ionic.
   3.   ?    permanent dipole-permanent dipole.
   4.   ?    van der Waals.