General Chemistry Spring 2009

In this clip I discuss predicting the products of four reactions (Question 1), and how to write the ionic and net ionic equation for one of the reactions (Q2 @7’ 51”). Question 3 (10’ 57”) asks for the electron configuration and the number of unpaired electrons for three elements. Using the same theme, an orbital diagram is focus of Q4 (18’ 58”). Question 5 (22’ 35”) is a multipart question beginning with the calculation of the frequency of an emission line in the hydrogen atom spectrum, then a calculation of the value of n that the electron falls to, a drawing of the energy level diagram for the hydrogen atom, and finally a calculation of the amount of energy required to ionize the electron. In Q6 (37’ 35”) effective nuclear charge is used to explain periodic trends.

In this clip I solve two sample problems from PS8, PS8.3 and PS8.7.

In this lecture we began discussing ACA#8 and mentioning the importance of explaining why particular mixtures are homogeneous or heterogeneous. Rules are not explanations. We reviewed the solution process and the kind of explanation needed for heterogeneous or homogeneous mixtures. Next we did a brief review of writing the products for a double replacement reaction and writing the ionic and net ionic equations. We did a brief introduction to colligative properties, and discussed how the concentration of particles is important. We then discussed four important ways of expressing concentration: weight %, molarity, mol fraction and molality. We ended the class by doing a problem using the four concentration definitions.

In this lecture we began with an inclass activity. We started discussing solutions. We covered solutions by beginning with important definition. From the perspective of phases we mentioned the morst important solutions. We looked at a video of the formation of asolution and talked about how we would describe the solution. We looked at several macroscopic examples of homogeneous (solutions) and heterogeneous mixtures. We talked about the importance of intermolecular attractive forces in predicting whether a mixture will be homogeneous or heterogeneous. We also looked at a particulate level representation of solutions. We continued our discussion of important terms in the solution process from the particulate level perspective.

In today's class we discussed the calculating the pH of a strong acid, a strong base, a weak acid and a weak base. We also looked a a weak diprotic acid to see how to calculate the pH of the solution.

In today's class we discussed the concentration terms weight% mol fraction, molarity and molality and did several sample problems. Near the end of class we began a discussion of colligative properties.

In this lecture we began by looking at what happens when water freezes. We then continued our discussion by reviewing types of solids. We then discussed different types of crystal systems solids can have. We focused on the cubic system and discuss simple cubic, body-centered cubic and face centered cubic. We looked at each of the unit cells for these systsms and discussed the relationship between edge length and atomic radisu. Near the end of class we did a sample calculation of a problem based on a cubic system..

In this segment I review each of the questions on the CHEM 1314 Exam #1 for Fall 2006. I do the problem and discuss some of the point assignments and some of the places where students went astray.

In this segment I review each of the questions on the CHEM 1314 Exam #1. I do the problem and discuss some of the point assignments and some of the places where students went astray.

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.