Final answer:
The primary intermolecular forces between hydrogen sulfide (H₂S) and a nickel(II) cation (Ni²⁺) are dipole-dipole interactions and ionic interactions due to the polarity of H₂S and the charge of the Ni²⁺ cation.
Step-by-step explanation:
The question concerns the identification of the type of intermolecular forces that would act between a hydrogen sulfide molecule (H2S) and a nickel(II) cation (Ni2+). Between these two, the most significant intermolecular force would be dipole-dipole interactions because hydrogen sulfide is a polar molecule due to the difference in electronegativity between hydrogen and sulfur. Additionally, since nickel(II) cation is a charged particle, there can be significant ionic interactions between the cation and the polar molecule of hydrogen sulfide.
Thus, while hydrogen sulfide also exhibits London dispersion forces, the forces due to its dipole and the interaction with the charged cation are stronger. Therefore, the answer to the student's question is that both dipole-dipole forces and ionic interactions are the primary intermolecular forces at play.