6.1 Energy and the First Law of Thermodynamics
Energy is the ability to do work. The SI unit of energy is the joule.
4.18J = 1 cal 1 Cal = 1kcal = 1000cal
|TYPES OF ENERGY|
1st Law of Thermodynamics
Energy cannot be created or destroyed (conservation of energy).
ΔE = q + w q = heat w = work
PV work (w = -PΔV)
|Signs for q and w|
|q > 0 heat is transferred into the system|
|q < 0 heat is transferred out of the system|
|w > 0 work is done on the system|
|w < 0 work is done by the system|