Today in chem we got our tests back. Not too many of us did very well on that. DLiebs himself said the average score was "not too good". But still, life goes on.
After taking our questions on the test and refusing to give any sort of curve on the test, Liebs began our new unit. Thermodynamics.
We began by discussing energy. We divided energy into kinetic energy (energy due to motion) and potential energy (energy due to position). To demonstrate this concept, Liebs used the example of a ball thrown in the air; as the ball slows on its ascent, it loses the initial kinetic energy it had in movement, and gains potential energy with its height. As it begins its decent it loses potential energy and gains kinetic energy as it falls faster and faster.
New Law: Conservation of Energy. Same deal as most other conservation laws. Energy cannot be created or destroyed; it can only be transformed. There is a limited amount of energy in the universe, but there's a lot of it.
We also learned that heat and temperature are two different things.
Temperature is the measure of kinetic energy of particles' random motion. (Measured in °C, °F or K)
Whereas heat is the total amount of energy transferred from an object of high temperature to one of low temperature. (Measured in J or Cal)
Another good thing to know is heat capacity. Heat capacity is the amount of heat required to raise a substance by 1° celsius. Heat capacity is different for each sample. For example a metal has a lower heat capacity than water, and a larger sample has a greater heat capacity than a smaller sample.
Specific heat capacity is a physical property measured in J/g°C. Basically, it is the amount of heat required to raise 1 gram of a substance by 1°C. (denoted by Cp
The Ultimate formula is as follows: q=m*Cp* ΔT.
Or heat = mass * specific heat * change in temperature
Thats it. I need to make cookies.
Good night y'all. Do the prelab and the worksheet he gave us.
Kathryn J can scribe next.
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