Heating and Cooling Curves

Front

What is the direction of thermal energy (heat) transfer?

Back

Thermal energy (heat) always moves from a high temperature object to a lower temperature object.

Front

What state of matter is present between points C and D on a heating curve?

Back

Liquid

Front

What happens to water molecules as heat is absorbed at 50 °C?

Back

The water molecules increase their kinetic energy.

Front

How are all phase changes classified?

Back

All phase changes are classified as physical changes.

Front

What is the heat released when 5 grams of water vapor condense to liquid water at 100 °C?

Back

11,300 j/g.

Front

Define 'heating curve'.

Back

A heating curve is a graphical representation of the temperature change of a substance as it is heated over time.

Front

What occurs during the melting phase?

Back

During the melting phase, a solid absorbs heat and changes into a liquid.

Front

What is the significance of the plateau in a heating curve?

Back

The plateau indicates a phase change where temperature remains constant as heat is added.

Front

What is the latent heat of vaporization?

Back

The latent heat of vaporization is the amount of heat required to convert a unit mass of a liquid into vapor without a change in temperature.

Front

What happens to the kinetic energy of molecules during condensation?

Back

During condensation, the kinetic energy of molecules decreases as they lose heat and transition from gas to liquid.