What happens when hot water is added to cold water in an insulated container?

• A. The hot water instantly evaporates upon contact with the cold water.
• B. No heat transfer occurs between the hot and cold water.
• C. Heat flows from the hot water to the cold water until both reach the same temperature.
• D. The cold water becomes colder while the hot water remains at its original temperature.

Answer: (C)

Verified step by step guidance

1. Understand the principle of heat transfer: Heat always flows spontaneously from a hotter object to a cooler one until thermal equilibrium is reached.
2. Recognize that when hot water is added to cold water in an insulated container, the system is isolated, so no heat is lost to the surroundings.
3. Apply the concept that the hot water will transfer heat to the cold water, causing the temperature of the hot water to decrease and the temperature of the cold water to increase.
4. Know that this heat exchange continues until both the hot and cold water reach the same final temperature, achieving thermal equilibrium.
5. Conclude that the statement 'Heat flows from the hot water to the cold water until both reach the same temperature' correctly describes the process, while the other options contradict the laws of thermodynamics.