Plans for the Week and Assignments: 1. FRIDAY(12/14): Molecular Mass, Ideal Gas Law, Kinetic Theory of Gases, and Diffusion. HW: Read pages 394409 and solve prob. 1, 3, 9, 11, 28, 29, and 39 on pages 411413. 2. MONDAY(12/17): Thermodynamic Systems, the Zeroth Law, the First Law, Thermal Processes, and Specific Heat Capacities. HW: Read pages 417428 and solve prob. 2, 7, 18, 30, and 40 on pages 444446. 3. TUESDAY(12/18): The Second Law, Heat Engines, Carnot's Principle, Entropy, and Review . HW: Read pages 428439 and solve prob. 46, 47, 57, 58, and 68 on pages 446447. 4. WEDNESDAY(12/19): TEST on Chap.14&15  Ideal gas Law, Kinetic Theory, and Thermodynamics. HW: Go to website for notes Chapters 16 & 17  Waves and Sound. 5. THURSDAY(12/20): LAB on Boyles Law. HW: Process lab data and write lab report. 6. FRIDAY(12/21): PostLab Discussion. Lab Report is due by end of class. HW: Have a safe and restful Holiday Break!
Very Important: If you have any questions or miss a class, see me before school (8:00  8:30 AM), during Lunch, 7th hour, or after school. Best to send an email to rpersin@fau.edu.
WEBSITE NOTES: Ch. 14 & 15  The Ideal Gas Law, Kinetic Theory, and Thermodynamics. 1. Each element in the periodic table is assigned an atomic mass. One atomic mass unit (u) is exactly onetwelfth the mass of an atom of carbon12. The mass of a molecule is the sum of the atomic masses of its atoms. 2. The number of moles n contained in a sample is equal to the number of particles N (atoms or molecules) in the sample divided by the number of particles per mole N_{A}. We then have the equation n = N/N_{A}, where N_{A} = 6.022x10^{23} particles per mole, known as Avogadro’s Number, from Amedeo Avogadro (17761856), Turin, Italy. 3. The number of moles is also equal to the mass m of the sample (expressed in grams) divided by the mass per mole (expressed in grams per mole ). This gives us the equation n = m/(mass per mole). The mass per mole (in g/mol) of a substance has the same numerical value as the atomic or molecular mass of one of its particles (in atomic mass units). 4. The mass of a particle (in grams) can be obtained by dividing the mass per mole (in g/mol) by Avogadro's number: m_{particle} = mass per mole/N_{A}. 5. The ideal gas law relates the absolute pressure P, the volume V, the number n of moles, and the Kelvin temperature T of an ideal gas, or PV = nRT, here we have R = 8.31 J/(mol∙K), the universal gas constant. An ideal gas is one that within a range of densities, temperature, volume, and pressure have a simple relationship. 6. An alternative form of the ideal gas law is PV = NkT, where N is the number of particles and k = R/N_{A} = 1.38x10^{23} J/K , a constant named after Ludwig Boltzmann (18441906), Austria, who developed the branch of Physics known as Statistical Mechanics. 7. Recall from Chemistry that a real gas behaves like an ideal gas if its density is low enough that its particles do not interact, except via elastic collisions. All gas laws use the absolute temperature unit, the Kelvin (K), named after William Thomson, Lord Kelvin (18241907). Water freezes at 273.15 K and boils at 373.15 K, with 0.00 K being absolute zero. 8. When a gas is kept at constant temperature, its pressure is inversely proportional to the volume. This is Boyle's Law P_{i}V_{i} = P_{f}V_{f} , named after Robert Boyle (16271691) from Ireland. 9. Also, when the pressure is kept constant, the volume is directly proportional to the temperature. This is the law of Charles and GuyLussac V_{i}/T_{i} = V_{f}/T_{f} , from Jacques Charles (17461823) and Joseph Louis GuyLussac (17781850), both from France. 10. Temperature is a quantity proportional to the average kinetic energy of the particles. This is based on Kinetic Theory, which assumes that (i) all matter is composed of tiny particles (atoms or molecules), and (ii) these particles are in constant motion. 11. The equation that we applies here is KE_{avg} = ½ mv^{2}_{rms} = 3/2 kT, where v_{rms} is the rootmeansquare speed of the particles, derived statistically. The internal energy U of n moles of a monatomic ideal gas is U = 3/2 nRT. 12. Diffusion is the process by which solute molecules move through a solvent from an area of higher concentration to an area of lower concentration. Fick’s Law, named after Adolf Eugen Fick (18291901), Germany, states that the mass of a solute that diffuses in time through a channel of known length and crosssectional area is given by m = (D·A·ΔC)t/L . In this equation, ΔC is the solute concentration difference between the ends of the channel, and D is the diffusion constant. 13. Thermodynamics is the study of heat and how it relates to the other forms of energy (mechanical, light, sound, electric, magnetic, atomic, and nuclear). The Zeroth Law of Thermodynamics states that two systems are in thermal equilibrium if there is no net heat flow between them when they are brought into thermal contact. 14. The First Law of Thermodynamics states that the total increase in thermal energy of a system is equal to the sum of the heat added to it and the work done on it, which is given by the equation ΔU = (U_{f} U_{i}) = QW. 15. A thermal process is considered quasistatic when it occurs slowly enough that a uniform pressure and temperature exist throughout the system at all times. The work done in any kind of quasistatic process is given by the area under the pressure versus volume graph. 16. An isobaric process is one that occurs at constant pressure. The work done when a system changes at constant pressure from initial to final volume is given by the equation W = P·ΔV = P(V_{f} V_{i}). 17. An isochoric process is done at constant volume and no work is done. An isothermal process is done at constant temperature. An adiabatic process takes place without the transfer of heat. 18. When n moles of an ideal gas change quasistatically from an initial to a final volume at a constant Kelvin temperature, the work done is given by W = nRT·ln(V_{f} /V_{i}). 19. When n moles of an ideal gas change quasistatically and adiabatically from an initial to a final Kelvin temperature, the work done is according to W = 3/2 nR(T_{i} T_{f}). 20. During an adiabatic process, and in addition to the Ideal Gas Law, an ideal gas obeys the relation P_{i}V_{i}^{γ} = P_{f}V_{f}^{γ}, where γ = c_{p}/c_{v}, which is the ratio of specific heat capacities at constant pressure and constant volume. 21. The molar specific heat capacity of a substance determines how much heat is added or removed when the temperature of n moles of the substance changes. This is given by the equation Q = C·n·ΔT. 22. For a monatomic ideal gas, the molar specific heat capacities at constant pressure and constant volume are, respectively, C_{P }= 5/2 R and C_{V }= 3/2 R, where R is the Ideal Gas Constant equal to 8.31 J/(mol·K). 23. For any type of an ideal gas, the difference between C_{P }and C_{V }is R, or C_{P } C_{V }= R. 24. There are many equivalent statements for the Second Law of Thermodynamics. In terms of heat flow, the second law declares that heat flows spontaneously from a substance at higher temperature to a substance at lower temperature. 25. The second law also states that natural processes always go in a direction that increases the entropy, S, unavailable energy, or disorder, of a system. ΔS = Q – W. 26. A heat engine continuously converts thermal energy to mechanical energy and does work. The efficiency, e, of a heat engine is expressed by the equation e = (Work done)/(Input heat) = W/Q_{H}. 27. Conservation of energy requires that the input heat of magnitude Q_{H} must be equal to the work done plus the heat of magnitude Q_{C} rejected or expelled to a cold reservoir. This gives us Q_{H} = W + Q_{C}. By combining the previous two equations we arrive at the result, e = 1 – (Q_{C} / Q_{H} ). 28. A reversible process is one in which the both system and its environment can be returned to exactly the same states they were in before the process occurred. An alternate statement for the second law was stated by French engineer, Sadi Carnot (17961832). 29. Carnot’s principle states that no irreversible engine operating between two reservoirs at constant temperature can have a greater efficiency than a reversible engine operating between the same temperatures. Furthermore, all reversible engines operating between the same temperatures have the same efficiency. 30. A Carnot engine is a reversible engine in which all input heat Q_{H} originates from a hot reservoir at a single Kelvin temperature, and all rejected heat Q_{C} goes into a cold reservoir also at a single Kelvin temperature. For the Carnot engine, we have Q_{C}/Q_{H} = T_{C}/T_{H}. 31. This gives an equation for the maximum efficiency that an engine can have operating between two fixed temperatures. e_{ Carnot} = 1  T_{C}/T_{H}. 32. A heat pump, air conditioner, or refrigerator uses mechanical energy to transfer heat from an area of lower to higher temperature. These are governed by the Law of Conservation of Energy with Q_{H} = W + Q_{C}. 33. The coefficient of performance of a refrigerator or air conditioner is given by the equation Coefficient of performance = Q_{C} /W. For the heat pump we have a similar relationship, Coefficient of performance = Q_{H}/W. 34. The change in entropy, ΔS, for a process in which heat enters or leaves a system reversibly at a constant Kelvin temperature is ΔS = (Q/T)_{R}, where the subscript R stands for "reversible." 35. In terms of entropy, the second law states that the total entropy of the universe does not change when a reversible process occurs (ΔS_{universe} = 0 J/K), and increases when an irreversible process occurs (ΔS > 0 J/K). 36. Irreversible processes cause energy to be made unavailable for the performance of work. This energy is given by W_{unavailable} = T_{o}·ΔS_{universe} where ΔS_{universe} is the total entropy change in the universe and T_{o} is the Kelvin temperature of the coldest reservoir into which heat can be rejected. 37. And still, we need these steps to solve any problem in Physics: (i) read the problem and identify the given variables (ii) determine what you are asked to solve for (iii) find the correct equation to use (iv) use Algebra, Trigonometry, and/or Calculus to isolate the unknown (v) substitutein the given information and simplify. 38. And still, we need these steps to solve any problem in Physics: (i) read the problem and identify the given variables (ii) determine what you are asked to solve for (iii) find the correct equation to use (iv) use Algebra, Trigonometry, and/or Calculus to isolate the unknown (v) substitutein the given information and simplify.

