This
tri in AP Chemistry we have been covering the topic of Thermodynamics. This
topic covers both enthalpy and entropy. 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. 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.
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. 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.
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. 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.
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 umbrella of
thermodynamics. Most of this unit had to do with math and I found that very
beneficial to my personal understanding of the unit. Equations and numbers make
some of the concepts easier to understand. With the equations visible to me and
understanding each of the factors in the equation, I can fully realize what is
going on in the process of the reaction. I would say that my participation was
there this week as I asked a lot of questions pertaining to some of the
problems in our worksheets. Overall, I would put my understanding with this
material at about an 8/10.
Here is a video previewing a step of our lab next
week.
