Unit 5 Flashcards
Phase Diagram
A graph of pressure and temperature that shows the conditions under which a substance exists.
STP
Standard Temperature and Pressure
Triple Point
The temperature and pressure at which the solid, liquid, and gas phases co-exists.
Critical Point
Where substance indicates the critical temperature and critical pressure.
Molar Enthalpy of Fusion
The amount of energy required to melt one mole of a solid.
Nonvolatile
Liquids that do not evaporate readily because of strong attractive forces between particles.
Deposition
The change of a gas directly to a solid.
Sublimation
The change of a solid directly to a gas.
Kinetic molecular theory
Particles are in constant motion.
Molar Enthalpy of Vaporization
The amount of energy as heat needed to vaporize one mole of a liquid.
∆H
Enthalpy of products - enthalpy of reactants.
Hess’ Law
Overall enthalpy change in a reaction is equal to the sum of the enthalpy changes for the individual steps in the process.
Endothermic
Heat energy is absorbed; products higher.
Exothermic
Heat energy released; products lower.
Enthalpy Change
Using Hess’ law; process equals the sum of the energy difference of products minus the sum of the energy difference of the reactants.
