This trimester in AP Chemistry thus far we have been covering the topic of Thermodynamics. This topic covers both enthalpy and entropy as well as a few other concepts. We spent lots of time in class doing worksheets and using our famous white boarding technique. This technique has been very beneficial for myself and many other classmates all year as it allows us to see our other peers' thoughts and ideas and use them to learn more. We also spent a little bit of time doing a quick mini-lab that involved precipitates and net ionic reactions.
In our introduction to Thermdynamics we discussed the difference between heat and temperature. From our discussion we concluded that heat is a measurement of the total energy that is present in the system while temperature is the measurement of the heat content of the system. In our introductory discussion, we also figured out that heat is due to the breaking or making of bonds. Temperature is also related to the transfer of heat. Lastly we learned that when heat leaves the system and goes to the surroundings it is considered an exothermic process and when heat goes into the system from the surroundings it is considered an endothermic process. All in all, to reflect on this concept, I thought it was quite simple to comprehend, although this would not really be the case for topics to come. Learning and understanding the differences between heat and temperature was fairly simple for me.
Next we moved onto calorimetry. Here we continued to work on distinguishing between endothermic and exothermic processes. We worked on some worksheets using the formulas that we learned for the change in heat. Change in heat is equal to the mass multiplied by the specific heat capacity and the change in temperature. Calorimetry is useful to us because from this method we can find the energy change in the system by finding the energy change in the surroundings, and this can be very important. We also talked about the enthalpy of fusion and the enthalpy of vaporization. Enthalpy of fusion has to do with the process of melting and the breaking of bonds. When vaporization occurs the rest of the bonds are broken. To reflect on calorimetry, this began to really test me, and I was having quite a bit of trouble with it. After spending more time learning about calorimetry and vaporization, I began to comprehend it a little more, although I still definitely need more work before the exam.
In our last topic we discussed entropy. Entropy can be defined as the possible number of microstates that are available to the system. It is represented as delta S in the equation. Entropy is greater than zero when melting or vaporizing takes place. It also occurs when the number of moles increases. Entropy can be calculated as the sum of the products minus the sum of the reactants. The last thing that involved entropy was Gibbs free energy law. This was used to figure out whether or not a process is thermodynamically favored. We also dived a little bit into standard state conditions and things of that nature. To reflect on these topics, I also thought they were very difficult at first. I had some trouble understanding how to apply the formulas and equations and solving. I also need more work on the topics of entropy and Gibbs free energy law before the exam.
These were all of the main ideas that we covered this week. Basically they all go hand in hand with each other as they all fall under the larger scope of thermodynamics. Most of this unit had to do with math and I found that to be much easier and more helpful to my understanding of the topics. Equations and numbers make some of the concepts easier to understand because you are using set equations and concrete things. With the equations visible to me and understanding each of the factors in the equation, I can fully understand and comprehend what is going on in the process of each reaction. I would say I definitely participated in class rather well as I spent much time struggling with worksheets and whiteboards and discussing thermodynamics with my table as well as participating in class discussions. I would rate my understanding of the material at this point of time at 6/10.
Gibbs free energy equation
