Concept:Boiling points reflect the strength of intermolecular attractions. Non-polar substances rely on weak London dispersion forces, whereas polar molecules and those capable of hydrogen bonding have much higher boiling points.
Formula:$$ \text{B.P.} \propto \text{IMF Strength} $$
Solution:- Ethyl alcohol (\( 78.4^\circ\text{C} \)) and Acetic acid (\( 118^\circ\text{C} \)) contain strong hydrogen bonding.
- Benzene (\( 80.1^\circ\text{C} \)) is a larger, highly polarizable aromatic ring with significant pi-cloud dispersion forces.
- Carbon tetrachloride (\( \text{CCl}_4 \)) is entirely non-polar with perfectly symmetrical tetrahedral geometry. It relies exclusively on standard London dispersion forces, and its boiling point is approx \( 76.7^\circ\text{C} \).
- Comparing these experimental values, \( \text{CCl}_4 \) inherently requires the least energy to boil.
Why other options are incorrect:The polar and hydrogen-bonded structures of the others, or the strong aromatic stacking of benzene, ensure their boiling points exceed that of \( \text{CCl}_4 \).
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