1. Thermodynamics And you

2. The foundation of this model Was structured ~ 1820s during the industrial revolution (steam engines relating work done to heat…) By the German physicist Rudolf Clausius And you wondered how his brother Santa Clausius named his favorite reindeer - ya (ha ha)

4. What is heat? (Q) Heat is energy that is transferred from a warmer system to a cooler system Uni-directional flow from hotter to colder until equilibrium is reached This is the 0th law of thermodynamics So it is said – so it shall be! I am not making this up – it is the 0th law!!

6. What is Temperature? Temperature – Kelvin – scale directly proportional to average kinetic energy of molecules Zero K = absolute zero – all motion stops Kelvin temp = Celsius temp +273 0 Zero K = -273 0 C 273 K = 0 0 C = 32 0 F (Water freezes)

7. The heat that is transferred From one system to another can be calculated through the equation: Q = m c Δt Where Q = heat energy m = the mass of the material in the system c = heat capacity of the material (material specific amt. of heat required to raise the Temp. of one g. of a sub., one unit of Temp. Δt = the change in temperature (in Kelvin)

8. Fun and exciting heat transfer problem 0.2 L (temp. = 353 K) of water is added to a second container with 1L of water (temp. = 293 K). At what temp. will the water reach thermal equilibrium? Hint hint: Q lost by one = Q gained by the other

9. If you answered 303 K then you are one smart cookie!!

10. When you add heat to a system The energy of the system will change (go up) or the system will do work – or both! Q = ΔE + W This is the 1 st law of thermodynamics! Energy can never be created or destroyed

11. Fun and exciting question 2 A process adds 250J of heat to a gas in a cylinder. The gas does 140J of work on a piston. What is the change in the internal energy of the gas?

12. If you answered 110 J then you are one smart cookie!

13. Now let’s relate what we know to the demo. Where did the heat energy that was transferred to the air come from? The chemical bonds in the reaction! It takes energy to break bonds – and energy is released when new bonds are formed So in this reaction – there was a lot of energy released when the new bonds were formed

14. PV = nRT The Ideal Gas Law Pressure x volume = #moles x gas constant x the temperature So in the demo when we increase the temp. (a lot) and kept the pressure constant (it was an open system) then the volume of the gas increases rapidly (thermal expansion due to an increase in temperature).

15. If PV = nRT Then P V = nR T Or v1/t1 = nR / P = v2/t2 So if T goes up – then so does V When all else is constant

16. The final question A gas is heated from 293K to 333K in a closed container at a constant volume. The initial pressure of the gas is 24.005 atmospheres. What is the final pressure of the gas?

17. Did you answer 27.339 atm.???? Great job

18. The 2 nd law The total entropy (disorder) of the universe is always increasing Therefore, no engine can be 100% efficient No perpetual motion machines!

19. The 3 rd Law As the Temp. of an object approaches absolute zero – the entropy of the system approaches a constant A perfect crystal at zero K has zero entropy

20. WOW That was a fun introduction into. Thermodynamics!