Ch. 16: 2nd Law of Thermodynamics

entropy

disorder of a system

-increase disorder=increase entropy

-evolved towards having higher entropy

2nd Law of Thermodynamics

-entropy of the system is always going up

reversible vs irreversible processes

-reversible: ex- ball rolled up and down a ramp, building a house

-irreversible: can only go in 1 direction/can’t go backwards (bc so disorganized); most processes; ex- burning logs in a fire

Direction of Thermal Energy transfer

-heat moves from hot → cold

*”feel cold”=heat leaving the body

macrostates vs microstates

-macrostates: given way can make a system

-microstates: # ways can make a system

! (factorial)

-0!=?

ex: 4!= 4 × 3 × 2× 1= 24

*only use positive integers

-0!=1

the macrostate that is most likely is…

-the one w/ the most microstates

-bc energy more evenly distributed; =equilibrium; higher entropy