General.chem.2_Lesson-3.-Heating-Cooling-Curve_015627

What does the heating curve represent in a substance's phase change?

A graph showing the temperature of a substance plotted against the amount of energy it has absorbed.

What is the definition of endothermic processes?

Processes that absorb energy from the surroundings.

What is the heat of fusion?

The amount of heat needed to melt a substance from solid to liquid at constant temperature.

What occurs during the phase change from liquid to gas?

Vaporization occurs, which requires the heat of vaporization.

What is the significance of a cooling curve?

It shows how the temperature changes as a substance cools down, indicating a decrease in energy.

What happens at 0°C during the heating of ice?

Ice begins to melt; the temperature stays constant while potential energy increases.

What energy change occurs during the condensation of gas to liquid?

Potential energy decreases while kinetic energy remains constant.

What two phases are present during freezing?

Solid and Liquid.

How does kinetic energy change when a substance is cooled?

Kinetic energy decreases as the temperature lowers.

Why does the heating curve show an endothermic process?

Because it absorbs energy, resulting in an increase in kinetic and potential energy.

What is the heat of condensation?

The amount of heat needed to condense a substance from gas to liquid at constant temperature.

What phases are present during vaporization?

Liquid and Gas.

What happens at 100°C during the heating of water?

Water boils, and the temperature remains constant while potential energy increases.

What do you understand by the term 'sublimation'?

The process where a substance changes directly from solid to gas.

What is meant by heat of solidification?

The amount of heat needed to freeze a substance from liquid to solid at constant temperature.

How do heating and cooling curves differ?

Heating curves show energy absorption while cooling curves show energy release.