Heating Curves

Energy and Phase Change When adding heat to a solid, energy added increases the temperature and entropy until the melting point is reached When the melting point is reached, all energy added is used to break intermolecular forces and increase the entropy (does not increase temp) During melting both liquid and solid are present Melting and freezing point are the same value

Water and Ice Ice Water and Steam Steam Heating Curve for Water Solid Melting Point

Evaporation When energy is added to a liquid, its temperature and entropy increase until the boiling point is reached Once boiling point is reached, all energy added breaks intermolecular forces and increases entropy (does not increase temp) Both liquid and gas present Boiling and condensation point are the same

Water and Ice Ice Water and Steam Steam Heating Curve for Water Boiling Point Liquid

After all liquid has evaporated only the gas phase remains and any heat added increases both temp and entropy

Water and Ice Ice Water and Steam Steam Heating Curve for Water Gas

Draw a cooling curve and describe the changes that occur during each phase change