A substance is cooled from 120°C to -10°C at constant pressure. During cooling, it changes from a gas to a liquid at 78°C, and then from a liquid to a solid at -5°C. Which of the following statements correctly describes these changes?
Show the answer and explanation
Correct answer
B. The liquid-to-solid change is called freezing.
Principle or equation
Changes of state: gas to liquid is condensation, liquid to solid is freezing, solid to gas is sublimation, liquid to gas is evaporation.
Why this answer is correct
At 78°C, the substance condenses from gas to liquid. At -5°C, it freezes from liquid to solid. Therefore, the liquid-to-solid change is correctly called freezing.
Example
Water vapor condenses to liquid water at 100°C, and liquid water freezes to ice at 0°C.
This published item includes a stored explanation and passed the platform’s publication workflow. It is independent preparation material, not a claim of an official or recalled examination question.