Thermo Flashcards
Isolated systems?
Don’t allow transfer of mass or energy in or out
e.g. thermos flask
Closed systems?
Allow transfer of energy in or out but mass remains constant
e.g. gas in a cylinder
Open systems?
Mass and energy can be transferred in or out
e.g. centrifugal compressor
Intensive properties?
Properties which are independent of mass/system size
Examples of intensive properties
Temp, density, pressure, specific enthalpy
Extensive properties?
Properties which are dependent/proportional to mass or system size
Can be converted to intensive by dividing one property by another e.g mass/vol = density
total energy/mass = specific energy
Examples of extensive properties
Volume, internal energy, enthalpy
State variables?
Describe state of the matter @ equilibrium
Independent of the path to reach them
Examples of state variables
Temp, pressure, vol, entropy, mass
Isothermal process?
System changes without temp changing
Remains in thermal equilibrium
e.g. refrigerator
Isobaric process?
System changes without pressure changing
e.g. boiling water to steam
Isocharic process?
System changes without volume changing
e.g. ideal Otto cycle / a pressure cooker
Adiabatic process?
System changes without any heat or energy transfer occuring
e.g. piston in car engine
Process functions?
Describe the route to move away from equilibrium, depend on path
Give finite amounts, rather than a change, when integrated
e.g. work, heat
Zeroth law of thermo?
When two objects are separately in thermal equilibrium with a third, they are all in thermal equilibrium