Energetics

What is enthalpy (H):

http://www.ausetute.com.au/enthchan.html

http://www2.chemistry.msu.edu/faculty/reusch/VirtTxtJml/energy1.htm#enrg1

Hess law and some calculations:

http://www.chem.tamu.edu/class/majors/tutorialnotefiles/enthalpy.htm

http://grandinetti.org/Teaching/Chem121/Lectures/Enthalpy/index.html

Entropy and the second law of thermodynamics:

http://www.secondlaw.com/two.html#time