General Chemistry Spring 2009

In this clip I worked out all of the problems on the Spring 2007 CHEM 1515 Examination 1.

In today's class we continued discussing buffers and how to look at a buffer as a common ion system. Now we looked at buffers and how they resist change in pH by reacting with any strong acid or strong base that is added. We did several calculations involving adding strong acid and strong base to a buffer.

In this lecture we started coverage of Chapter 3. I introduced synthesis (formation) reactions and combustion reactions. We predicted products of synthesis and combustion reactions and balanced these equations. We also define a mol, and talked about the mass of one atom, or formula unit in units of atomic mass units and in units of grams.

In today's class we discussed temperature dependence of the equilibrium constant, and the relationship of free energy and the equilibrium constant. We then started discussing acids and bases, specifically the Arrhenius definition of an acid and base.

In this lecture we finished up Chapter 3 by discussing stoichiometry. We talked about how to read chemical equations, how to pullout stoichiometric conversions and how to perform simple quantitative calculations. We finished class talking about limiting reagent problems. We used a particular approach to solve limiting reagent problems. We also discussed the importance of using this approach to receive full credit on this type of problem.

In this segment I Worked out all of the problems on the Exam #3 for the Fall 2006 semester. This will be an excellent review for the final.

In this lecture we began by recognizing the top scores on Exam I. We did one more sample problem doing calculations with unit cells and density. We then continued our discussion of solids by talking about ionic compounds. We looked at the cesium chloride structure and the sodium chloride structure. We talked about cubic holes (CsCl structure) and octahedral holes (NaCl structure). We looked at diamond and recognized the face-centered cubic structur of carbon atoms, and then discussed the tetrahedral holes occupied by four additional carbon atoms,

In this lecture we summarized the the experiments using the OSU calorimeter and the bomb calorimeter, in terms of the first law of thermodynamics. We view a particulated level animation developed by the Molecular Workbench (www.concord.org) to demonstrate how heat is transferred between two gases separated by a gold barrier. We also talked about the relationship between enthalpy and internal energy. Near the end of class we discussed some of the characteristics of enthalpy. We discussed how the balance of the chemical equation effects the enthalpy for a reactions, how the enthalpy changes when we reverse a chemical reaction, and how the enthalpy of a reaction depends on the phase of the reactants and products.

In this clip I solve some sample problems from PS5. In the first problem I solve for the molar mass of an unknown compound. Next I discussed some of the issues related to PS6.8. Then I talked about issues related to PS6.5. Near the end of the Help Session I did a sample problem like PS6.1c.

In this clip I go over the Chem 1515 web site. How to locate the web site from two different addresses; the structure of the CHEM 1515 main web page; how to logon to your Personal Page (and get some extra credit); how to access your Personal Page; important components of your Personal Page; the Assignment Page; PLE Page; ACA Page, Grades Page, Problem Set Page; and other useful information. There is probably more detail here than in the first lecture.