Use your knowledge about intermolecular forces to explain why each pair has a different boiling point:
Water (100 °C) and nonane, C9H20 (150 °C)
Hydrogen fluoride, HF (20 °C) and hydrogen chloride, HCl (-85 °C)
Acetone, (CH3)2CO (56 °C) and butane, C4H10 (-1 °C)
Chloromethane CH3Cl (-24 °C) and chloropropane CH3CH2CH2Cl (47 °C)