A cooling curve for water shows a horizontal segment at 0 °C where the temperature…
PHYSICS · Single correct · AP · Physics 2: Algebra-based · Thermodynamics · Thermodynamics
Problem
A cooling curve for water shows a horizontal segment at 0 °C where the temperature remains constant for several minutes as liquid water becomes ice. Which statement most accurately describes the direction of heat flow and classification of this process?
(a) Heat is absorbed by the system from the surroundings; the process is endothermic.
(b) Heat is released by the system to the surroundings; the process is exothermic.
(c) No net heat is exchanged because the temperature is constant; the process is neither endothermic nor exothermic.
(d) Heat is released by the surroundings to the system; the process is exothermic.