General Chemistry Spring 2009

In this lecture we began by discussing the energy of the electron in the Bohr Model of the hydrogen atom. The lowest energy the electron can have is when it is in n = 1 level. As the electron moves to higher levels (n =2, n = 3, etc.) the electron must absorb energy. An atom with an electron in an energy level greater than n = 1 is said to be in an excited state. We talked more about the energy of the levels the electron can occupy in a hydrogen atom. Next we discussed the shell model for the atom. We reviewed the ionization energy of the first twenty elements in the periodic table. Based on the ionization energies and our understanding of the relationship between the charge on the nucleus and the distance the electron can be from the nucleus we arrived at the idea that electrons occupy different shells. We then looked at photoelectron spectra data and found that electrons in shells (shells greater than n = 1) had different energies. We introdcued the idea of subsehlls to explain the different energies of el

In this lecture we continued our discussion of enthalpy with a brief review of several points we discussed in lecture from October 17, 2006. Following the brief review we discussed Hess' Law and how we can use the idea to determine the change in enthalpy for a new reaction given the enthalpy of reaction for several other reactions. We did several examples using Hess Law. We introduced the very important definition of a formation reaction and then developed a useful mathematical relationship that we use to calcualte the enthalpy of reaction using the enthalpy of formation for the reactants and products.

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.

This is the lecture that Kerry covered. In this lecture Kerry introduced calorimetry measurements and calculations. She reviewed the relationship between heat, amount of substance, specific heat and change in temperature. She also discussed experiments using the OSU calorimeter and the bomb calorimeter.

In this lecture we continued our discussion of reaction types. In this class we covered neutralization reactions and single replacement reactions. There is a list of acids and bases that everyone must know, and you have to pay close attention to the strong acids and the weak acids because their ionic equations are different. We also looked at strong bases and weak bases. At the end of this lecture we defined molarity and looked at a few examples of problems using molarity.

In this lecture we discussed double replacement reactions. We did a quick review of the synthesis and combustion reactions. We also discussed the solubility table and looked at the conductivity data that everyone had generated in the PLE for the class.

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 lecture we introduced the concept of a formula. We discussed percent composition and how to determine the empirical formula a variety of ways. We also talked about the molecular formula and how to use the molecular mass to determine the molecular formula.

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 this lecture we discuss naming ionic and covalent compounds. We worked several examples.