If energy is added to a boiling liquid at its boiling point, what will happen?

• A. The liquid will freeze.
• B. The temperature of the liquid will increase.
• C. The liquid will convert to gas without a temperature change.
• D. The pressure of the liquid will decrease.

Answer: (C)

Verified step by step guidance

1. Understand that at the boiling point, a liquid is in equilibrium with its vapor, meaning the liquid and gas phases coexist.
2. Recall that when energy (heat) is added to a boiling liquid, the energy goes into breaking intermolecular forces rather than increasing temperature.
3. Recognize that this energy used to convert the liquid to gas is called the latent heat of vaporization.
4. Since the temperature remains constant during the phase change, the added energy causes the liquid to change phase from liquid to gas without a temperature increase.
5. Therefore, the correct interpretation is that the liquid will convert to gas without a temperature change when energy is added at its boiling point.