Question

heating curve for h₂o
given the heating curve of water, what is happening to potential and kinetic energy during segment cd?

1. the potential energy and kinetic energy both increase
2. the potential energy is constant while the kinetic energy increases
3. the potential energy increases while the kinetic energy is constant
4. the potential energy increases while the kinetic energy decreases

Explanation:

In a heating curve for water, segment CD occurs when water is boiling (liquid to gas phase change). During a phase change (like boiling), temperature (related to kinetic energy, since \( KE \propto T \)) remains constant, so kinetic energy is constant. Heat added goes into increasing potential energy (breaking intermolecular bonds for phase change). So potential energy increases, kinetic energy is constant.

Answer:

the potential energy increases while the kinetic energy is constant (corresponding to the orange option: "the potential energy increases while the kinetic energy is constant")