The heats of vaporization for CS2, C2H5OH, and H2O are 26.8, 38.6, and 40.6 kJ/kg·mole, respectively. What is the sequence of decreasing intermolecular forces among these liquids________________?
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Answer: A. H2O > C2H5OH > CS2
Explanation
Higher heats of vaporization reflect stronger intermolecular forces holding liquid molecules together. Water possesses extensive hydrogen bonding, giving it the highest heat of vaporization. Ethanol has weaker hydrogen bonding than water, while carbon disulfide relies on weak dispersion forces. Intermolecular forces determine physical properties like boiling points and latent heats. Hydrogen bonds are significantly stronger than standard van der Waals dipole interactions. Heat of vaporization measures the energy needed to transform liquid molecules into vapor.
Solvent selection in chemical extraction depends heavily on understanding intermolecular forces. Thermal distillation columns require more energy to separate liquids with high vaporization heats. Boiler and condenser designs must account for latent heat variations across different fluids. Option B incorrectly places carbon disulfide above hydrogen-bonded liquids. Option C incorrectly ranks carbon disulfide higher than ethanol in intermolecular strength. Option D places carbon disulfide first, ignoring its weak non-polar dispersion forces.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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