Thermodynamics Flashcards
What do Delta H, S, and G represent?
EnThalpy, Entropy, and Spontaneity.
What is the formula to calculate delta g?
Delta g = delta H - Delta S T
Contrast Exothermic and Exergonic?
Exothermic is the release of heat during a reaction- negative delta h.
Exergonic is a favorable, spontaneous reaction– negative delta g.
What is deltaG°, what is the equation?
free energy change as a reaction goes from standard condition to equilibrium.
deltaG° = -RT lnK
Describe enthalpy
Enthalpy describes the change of heat in a system. If heat is gained then it’s a positive delta h(endothermic) If heat is lost then the delta h is negative(exothermic).
Contrast the entropy of cyclic vs linear molecules
Cyclic molecules have less energy because they can’t freely move as much as linear molecules.
What is Hess’s Law
Change is energy = sum of energy of products - sum of energy of the reactants.
Bond energy delta h
Delt H = Bonds broken - bonds formed.
What is the formula for calculate heat change?
q= mcdelta T
mass, heat capacity, and change in temperature.
Describe calorimeter
This technique is used to calculate the amount of heat exchange in a system. Measure the temperature before and after the reaction occurs. Plug it into q=mcat to find the heat exchange during the reaction.
What is heat capacity?
The amount of energy needed to raise the temperature 1 degree celsius.
What is the formula for heat capacity?
rearrange q=mc delta t
c= q/m delta t.
Relate phase changes and enthalpy
The same enthalpy , but the opposite sign.
What is the formula for change in energy of the system?
Delt E = q - P (delta V)
Describe the sign convention of PV work.
If work is done on the system then it’s +
If work is done by the system then it’s - .
