Supplemental Instruction
Iowa State University / Leader: / Grant DeRocher
Course: / Chem 167
Instructor: / Houk
Date: / 04/14/13
Possibly useful equations:
∆E= q + w Kinetic energy = ½ mv2
q=mc∆T q=nCp∆T Calibration q= Ccalorimeter x ∆T
∆H= n x ∆Hphase change ∆G=∆H-T∆S
∆So=∑v*Sof(product) - ∑v*Sof(reactants)
∆Go=∑v*Gof(product) - ∑v*Gof(reactants)
eqns 11.4a, 11.6, 11.7 t1/2=ln2/k
k= Ae-Ea/RT K=CceqDdeqAaeqBbeq
1. If 374 J of heat is added to a gas that does 117 J of work as a result, what is the change in the energy of the system?
2. If 180 g of copper wire gains 310 J of heat, what is the change in temperature of the wire? Copper has a specific heat of 0.384 J/g*C
3. Write a formation reaction for (a) CH4 (b) HCl
4. The phase change between graphite and diamond is difficult to observe directly. Both substances can be burned however. From these equations, calculate ∆H for the conversion of diamond into graphite.
C(s, graphite) + O2 CO2 H=-393.51 kJ
C(s, diamond)+ O2 CO2 H= -395.94 kJ
5. For the reaction 6X (g) → 7X2 (g), will ΔS be positive, negative or zero? Circle the correct answer.
ΔS positive ΔS negative ΔS zero
6. Calculate ∆Go at 45 degrees C the reaction where ∆H= -86.6 kJ; ∆S= -382 J/K
7. Using tabulated thermodynamic data, calculate ∆G for this reaction:
(a) Mg3N2(s)+ 6H2O(l) 2NH3(g) + 3Mg(OH)2 (s)
Mg3N2= -115.3kJ/mol
8. What is the rate law expression for the following reaction? Show work for partial credit.
A + B → AB
Initial Concs. (M) Initial Rate
Exp [A] [B] (M/min)
1 0.50 0.50 3.0x10-4 Rate law:
2 0.50 1.20 1.08x10-3
3 0.50 0.40 1.20x10-4
4 0.25 0.40 0.60x10-4
9. A reaction occurs by the mechanism shown below. Fill in the information requested for this reaction.
A + B + C AB + C* fast Overall reaction ______
AB + C * + A A* slow
A* + A 3A + BC fast Rate law: rate = ______
Reaction order ______
Reactive Intermediate(s, there may be more than one)
\
______
10. Write equilibrium expressions for reach of the following reactions:
(a) H2(g) + I2(g) 2HI(g)
(b) CaCO3(s) Ca2+(aq) + CO32-(aq)
11. For the following, are the products or reactants favored?
AgCl(s) Ag+(aq) + Cl-(aq) K= 1.7x10-10
If we have time, I will work through more problems from the most recent sections we’ve covered in chapter 12 that might be useful. If we don’t get that far it might serve you well to do some of these problems on your own. Try them and if you have questions you can ask me or bring your questions to the review Tuesday night with the professor.
Here are some other things that it might be useful to know how to do for the test:
Be able to calculate calorimetry problems pg 294
Be able to calculate heats of reaction
Be able to do stoichiometry given a thermochemical equation
Know the three laws of thermodynamics and what that means for problem solving.
The following three statements refer to Appendix E:
1. Know what ∆Hf means and how to use it in a problem.
2. Know what ∆Gf means and how to use it in a problem.
3. Know what S means and how to use it in a problem.
Know table on pg 331 table 10.2
Know what to have on the x-axis for a linear graph of 0th order, 1st order, and 2nd order equation
Know half-life and how to calculate it.
Know table 11.1 dealing with elementary reactions-easy to memorize
-know what catalysts, intermediates, and rate determining steps are and how to find them.
Know how to solve gas phase equilibria problems using partial pressures
The concentrations of liquids and solids are 1 in heterogeneous equilibrium reactions.