Question

When water heats up at 0 degrees Celcius (given the heating curve of water), which of the following statements is true?

A) the average kinetic energy of the particles is increasing as heat is being absorbed
B) the average distance between the molecules is decreasing
C) the number of hydrogen bonds between the molecules is increasing
D) the potential energy of the substance is decreasing

Answer 1

A) the average kinetic energy of the particles is increasing as heat is being absorbed.

Step-by-step explanation:

When water is heated up at 0 degrees Celsius, it is undergoing a phase change from solid to liquid (melting). During this phase change, the temperature of the water remains constant even though heat is being absorbed. This is because the heat energy is being used to break the hydrogen bonds between the water molecules, which requires energy but does not raise the temperature of the substance. As a result, the average kinetic energy of the water molecules is increasing, but the potential energy remains constant. Once all the ice has melted, the temperature of the water will begin to rise again, indicating that the heat energy is now being used to increase the kinetic energy and temperature of the liquid water.