Energy and Enthalpy Changes in Physical States

Flashcards covering key concepts related to energy and enthalpy changes during physical state changes.

Delta H (ΔH)

The change in enthalpy during a reaction, indicating heat absorption or release.

Endothermic Process

A process that absorbs heat from the surroundings, resulting in a positive ΔH.

Exothermic Process

A process that releases heat to the surroundings, resulting in a negative ΔH.

Cooling Curve

A graph that represents the temperature of a substance as it cools and changes state.

Phase Change

The transition of a substance from one state of matter (solid, liquid, gas) to another.

Heat Capacity

The amount of heat required to raise the temperature of an object by one degree Celsius.

Specific Heat Capacity

The amount of energy required to raise the temperature of one gram of a substance by one degree Celsius.

Dissociation

The process in which a compound separates into ions or molecules when dissolved.

Combustion Reaction

An exothermic reaction where a substance combines with oxygen, producing heat and light.

Sublimation

The process by which a solid changes directly into a gas without passing through a liquid state.

Deposition

The process by which a gas changes directly into a solid without becoming a liquid first.

Delta H of Fusion

The heat absorbed or released during the phase change from solid to liquid.

Delta H of Vaporization

The heat absorbed or released during the phase change from liquid to gas.

Knowledge Check

An informal assessment to gauge understanding of a topic or concept.

Activated Hot Pack

A device containing chemicals that generate heat through an exothermic reaction when activated.