1st law of thermodynamics 

the total energy of the universe is constant 
 
2nd law of thermodynamics 

the total entropy of the universe is always
incresing 
 
3rd law of thermodynamics 

the entropy of every pure perfectly formed crystalline substance at absolute zero is zero 
 
a negative delta H is what kind of reaction? 

exothermic 
 
a positive delta H is what kind of reaction? 

endothermic 
 
definition of entropy 

measure of disorder 
 
4 rules of entropy 

1. gases have greater entropy than liquids 2. liquids have greater entropy than solids 3. entropy of a system increases as temp increases 4. in a chemical reaction the side with more mols has greater entropy 
 
thermochemistry 

the heat changes that occur during chemical reactions 
 
energy 

the capacity for doing work or supplying heat 
 
what is the energy stored in chemical bonds called? 

chemical potential energy 
 
heat 

energy that transfers from one object to another becuase of a temperature difference between them. 
 
calorie 

the quantity of heat needed to raise the temp of 1g of pure water 1 degree C 
 
kilocalorie 

equal to 1000 calories 
 
joule 

the SI unit of heat and energy named after the English physicist James Prescott Joule 
 
how many joules in 1 calorie? 

4.184 Joules 
 
Heat capacity 

the amount of heat needed to increase the temp of an object exactly 1 degree C 
 
Specific heat capacity 

the amount of heat it takes to raise the temp of 1g of the substance 1 degree C 
 
calorimeter 

a device for measuring heat changes 
 
enthalpy 

the heat content of a system at constant pressure 
 
what does delta H stand for? 

heat of reaction or enthaply of reaction 
 
Hess's law 

if you add two or more thermochemical equations to get the final equation, then you can also add the heat of reaction to five the final heat reaction. 
 
standard heat of formation 

the change in enthaply that accompanies the formation of one mol of a compound from its elements with all substances in their standard states at 25 degrees C 
 
free energy 

energy that is available to do work 
 
spontaneous reactions 

reactions that occur naturally and that facor the formation of products at the specified conditions 
 
nonspontaneous reactions 

reactions that do not facor the formation of products at the specified conditions 
 
standard entropy 

the entropy of a substance in its stable state at 25 degrees C 
 
Gibb's free energy 

the maximum amount of energy that can be coupled to another provess to do useful work 
 
CaCO3(s) + 176kJ > CaO(s) + CO2(g) a. caculate the energy required to decompose 5.20 mol of CaCO3
b. how many kcal are required? 

a. 915 kJ
b. 219 kcal 
 
SO3 + H2O > H2SO4 + 129.6 kJ
how much heat in kJ and kcal is released when 583 grams of SO3 reacts with water? 

a. 
 
2CO2 + 43.9 kJ > 2CO + O2
how many molecules of CO2 can be decomposed by the addition of 22.2 kJ of heat? 

6.09x10^23 molecules 
 
2C2H6(g) + 7O2(g) > 4CO2(g) + 6H2O(l)
calculate delta H, delta S, and delta G 

a. H= 3119.6 kJ/mol
b. S= 620.7 J/kmol
c. G= 2934.57 kJ/mol 
 
2NO2(g) > N2O4(g)
calculate delta H,S and G 


 
2Fe + 3CO2 + 26.3kJ > Fe2O3 + 3CO
a. calculate kJ for 7.3 mols of Fe
b. is this a positive or negative enthalpy change? 

a. 96 kJ
b. positive 
 
2Mg + O2 > 2MgO + 288kcal
a. calculate kcal for 0.12 mols of Mg
b. calculate kJ 

a. 17kcal
b. 71kJ 
 
C2H4 + 3O2 > 2CO2 + 2H2O + 1.39x10^3
calculate the heat for 1.87g of C2H4 

92.7kJ 
 
I2(s) > I2(g)
calculate delta H,S and G 

H=62.438 kJ/mol
S=144.56 J/kmol
G=19.327 kJ/mol 
 
3CO(g) + Fe2O3(s) > 2Fe(s) + 3CO2(g)
calculate delta H,S and G 

H= 24.7 kJ/mol
S= 16.36 J/kmol
G= 29.4 kJ/mol 
 
2NO2(g) > 2NO(g) + 2H2O(g)
calculate delta H,S and G 

H= 369.5 kJ/mol
S= 319.05 J/kmol 
 
2NO(g) + O2(g) > 2NO2(g)
calculate delta H,S and G 

H= 144.1 kJ/mol
S= 146.54 J/kmol 
 
2HF(g) > H2(g) + F2(g) at 1030. C
calculate delta H,S and G 

H= 542.2 kJ/mol
S= 14.10 J/kmol
G= 560.6 kJ/mol 
 
NaOH(s) + HCl(aq) > NaCl(aq) + H2O(l)
at 85.0 C
calculate delta H,S and G 

H= 100.33 kJ/mol
S= 64.4 J/kmol
G= 123.4 kJ/mol 
 