The process H₂O(l) → H₂O(g) at 373 K and 1 atm has a positive entropy change
CHEMISTRY · Single correct · AP · Chemistry · Thermochemistry · Thermochemistry
Problem
The process H₂O(l) → H₂O(g) at 373 K and 1 atm has a positive entropy change. Which of the following statements best explains this observation?
(a) Energy is absorbed as heat during vaporization, so the internal energy of the molecules increases, raising entropy.
(b) Hydrogen bonds are broken during vaporization, and breaking bonds always increases entropy.
(c) Gas–phase water molecules occupy a much larger volume than liquid molecules, increasing the number of accessible microstates.
(d) In the gas phase the molecules move much faster, and higher molecular speed directly causes higher entropy.