Final answer:
The intermolecular forces in C7H16 (heptane) are stronger than in C5H12 (pentane) due to the larger size and surface area of the molecule.
Step-by-step explanation:
The strength of intermolecular forces in organic compounds such as alkanes (CnH2n+2) increases with molecular size and surface area. In this case, C7H16 (heptane) has more carbon and hydrogen atoms than C5H12 (pentane), resulting in a larger molecule and a larger surface area for intermolecular interactions. Therefore, the intermolecular forces in C7H16 are stronger than in C5H12. The primary intermolecular force in both compounds is London dispersion forces, but the strength of these forces increases with larger molecules.