CHEM 1212: The Solid State

These flashcards cover key terms and concepts regarding phase changes, heating curves, and energy calculations relevant to solid-state chemistry.

Phase Change

A change in the physical form but not the chemical identity of a substance.

Fusion

The transition from solid to liquid, also known as melting; an endothermic process.

Freezing

The transition from liquid to solid; an exothermic process.

Vaporization

The transition from liquid to gas; an endothermic process.

Condensation

The transition from gas to liquid; an exothermic process.

Sublimation

The transition from solid to gas; an endothermic process.

Deposition

The transition from gas to solid; an exothermic process.

Heating Curve

A graphical representation showing the relationship of temperature and heat input of a system as it is heated over time.

Enthalpy of Fusion (ΔHfus)

The amount of energy required to convert a solid to a liquid.

Enthalpy of Vaporization (ΔHvap)

The amount of energy required to convert a liquid to a gas.

Energy Change

In temperature change, kinetic energy increases, while during phase changes, potential energy increases.

Cooling Curve

A graphical representation that shows the exothermic process as a substance changes from a gas to a solid.

Specific Heat Capacity

The amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius.

Heat Calculation

Total heat (q) during a phase change can be calculated using q = m x c x ΔT for temperature changes and q = n x ΔH for phase changes.

Intermolecular Forces (IMFs)

Forces that hold molecules together, which must be overcome during phase changes.

Heat of Vaporization vs. Heat of Fusion

ΔHvap > ΔHfus because more energy is required to break all intermolecular forces during vaporization than during fusion.

Joules to Kilojoules

Conversion of energy units where 1 kJ = 1000 J.

Phase Changes and Kinetic Energy

During phase changes, temperature does not change while kinetic energy remains constant, but potential energy increases.

Molar Heat Capacities

Specific heat values measured per mole of substance.