During the change of state from liquid to vapor at constant pressure, what type of heat is involved?

The correct choice involves latent heat because it specifically refers to the heat energy absorbed or released during a phase change at constant pressure, without a change in temperature. When a liquid changes into vapor (or steam), it requires energy to overcome the intermolecular forces, allowing the molecules to separate and transition to the gaseous state. This energy is not used to raise the temperature of the substance but is essential for the phase transition itself.

In the case of vaporization, as heat is added to the liquid, the temperature remains stable until the complete transformation into vapor occurs. This absorption of heat at a constant temperature is characteristic of latent heat, which is crucial for processes like boiling and condensation.

The other types of heat mentioned do not fit this scenario. Sensible heat refers to the heat exchanged that results in a temperature change, while conductive heat pertains to the transfer of thermal energy through direct contact. Basal heat is not typically recognized as a standard term in thermodynamics. Thus, focusing on how latent heat facilitates the phase change clarifies its role in the process described.