Which of the following best explains why condensation of water vapor releases heat to…
PHYSICS · Single correct · ISC · Physics · Behaviour of Perfect Gases and Kinetic Theory of Gases · Heat and Thermodynamics
Problem
Which of the following best explains why condensation of water vapor releases heat to the surroundings?
(a) Gas-phase water molecules must slow down to enter the liquid phase; the loss of kinetic energy is released as heat to the surroundings.
(b) Gas-phase water molecules form stronger intermolecular (hydrogen-bond) attractions in the liquid phase; the decrease in potential energy is released as thermal energy to the surroundings.
(c) Heat is given off because hydrogen bonds in liquid water break during condensation, and breaking these bonds releases energy.
(d) As water vapor condenses, the decrease in volume at constant external pressure allows the system to do PΔV work on the surroundings, which appears as heat released.