Final answer:
Miscible liquids can dissolve in each other, while immiscible liquids cannot. The intermolecular forces between two solvents in a miscible pair depend on their polarities.
Step-by-step explanation:
Miscible and immiscible liquids
Miscible liquids are those that can dissolve in each other, while immiscible liquids cannot. The solubility of liquids is primarily determined by their polarity. Liquids with similar polarities are usually miscible, while liquids with different polarities are usually immiscible.
Intermolecular forces
The intermolecular forces between two solvents in a miscible pair depend on their polarities. For polar or hydrogen bonding liquids, the dipole-dipole attractions (or hydrogen bonding) between solute and solvent molecules are at least as strong as those within the pure solute or solvent. Nonpolar liquids are miscible with each other because the strengths of solute-solute, solvent-solvent, and solute-solvent intermolecular attractions are similar.
An example of a miscible pair with dipole-dipole attractions is ethanol and water. They completely blend and dissolve into one another. An example of a miscible pair with weak dispersion forces is nonpolar lighter fluid and iodine.