the electron cloud of hf is smaller than that of f₂, however, hf has a much higher boiling point than f₂…

the electron cloud of hf is smaller than that of f₂, however, hf has a much higher boiling point than f₂ has. which of the following explains how the dispersion - force model of intermolecular attraction does not account for the unusually high boiling point of hf?\na f₂ is soluble in water, whereas hf is insoluble in water.\nb the f₂ molecule has a greater mass than the hf molecule has.\nc liquid f₂ has weak dispersion force attractions between its molecules, whereas liquid hf has strong ionic interactions between h⁺ and f⁻ ions.\nd liquid f₂ has weak dispersion force attractions between its molecules, whereas liquid hf has both weak dispersion force attractions and hydrogen bonding interactions between its molecules.
Answer
Brief Explanations:
- Option A: Solubility in water is not related to boiling point differences.
- Option B: (F_2) has a smaller mass than (HF) (molar mass of (F_2 = 38\space g/mol), molar mass of (HF=20\space g/mol)), so this is incorrect.
- Option C: (HF) is a covalent compound, not ionic. There are no (H^+) and (F^-) ions in liquid (HF) in the sense of ionic interactions.
- Option D: (F_2) has only weak dispersion (London) forces. (HF) has both weak dispersion forces (due to its electrons) and strong hydrogen - bonding (because of the (H - F) bond where (F) is highly electronegative). Hydrogen bonding is a much stronger intermolecular force than dispersion forces. A substance with stronger intermolecular forces (like (HF) with hydrogen bonding) will have a higher boiling point as more energy is required to break these intermolecular attractions.
Answer:
D. Liquid (F_2) has weak dispersion force attractions between its molecules, whereas liquid (HF) has both weak dispersion force attractions and hydrogen bonding interactions between its molecules.