Question

list all the Coulomb and van der Waals interactions for:

a. two carbon monoxide molecules

b. a calcium carbonate ion-pair

c. benzaldehyde

Answer 1

a. As the there's a difference in electronegativity of C and O, carbon monoxide molecule has partial positive and negative charges on C and O respectively making it a dipole. This results in the van der Walls or Dipole-Dipole interactions between two CO molecules. Also, the two partially charged carbon atoms shall repel each other resulting into Coulomb interactions.

b. As calcium carbonate is an ionic compound, there is no dipole formation and hence, no van der Walls interactions. The electrostatic interactions of repulsion and attraction exist between charged ions.

c. The aldenyde bond in benzaldehyde does induce some dipole moment to the molecule hence dipole dipole interactions exist in it. Furthermore because of this partial charges, coulomb interactions also exist between benzaldehyde molecules.