Thermochemistry and Thermodynamics

state function

a function that only depends upon the initial and final states of the system, being independent of the pathway taken

zeroth law

concept of thermal equilibrium and temperature

conservation of energy

energy can not be destroyed or created, but converted from one form to another

spontaneous process

increase in entropy — G < 0, H < 0, S > 0

adiabatic

no heat in or out

isothermal

same temperature

isochoric

same volume

isobaric

same pressure

system does work on surroundings

-w

surroundings does work on system

+w

condution

heat transfer via molecular agitation within a material (but not involving net movement)o

convection

heat transfer due to the motion of a fluid (including gases)

radiation

heat transfer via electromagnetic radiation

bond breaking is ____

endothermic

bond making is ____

exothermic

spontaneous at all temperatures

H: -

S: +

-TS: -

nonspontaneous at all temperatures

H: +

S: -

-TS: +

spontaneous at low temperatures

H: -

S: -

-TS: +

spontaneous at high temperatures

H: +

S: +

-TS: -

solid to liquid

fusion

liquid to gas

vaporization

gas to solid

sublimation

liquid to solid

crystallization

gas to liquid

condensation

gas to solid

deposition

phase diagrams

triple point: the unique combination of temperature and pressure at which all three phases

critical point: the temperature and pressure where a substance can no longer exist as both a liquid and a gas, but instead as a supercritical fluid