Answer: HF-dipole- dipole interaction
CH3OH- dipole-dipole interaction
CaCl2- ion-ion interaction
Explanation:
Both CH3OH and HF possess permanent dipoles which interact with water leading to the dissolution of the above named substances. Remember that water also possesses a permanent dipole. Which can interact with the dipoles on other polar molecules. CaCl2 is purely ionic and interacts with water via ion-dipole mechanism.