Syllabus concepts to know

• B.4.1 that the first law of thermodynamics as given by Q = ΔU + W results from the application of conservation of energy to a closed system and relates the internal energy of a system to the transfer of energy as heat and as work
• B.4.2 that the work done by or on a closed system as given by W = PΔV when its boundaries are changed can be described in terms of pressure and changes of volume of the system
• B.4.3 3 3 that the change in internal energy as given by ΔU = Nk ΔT = nRΔT of a system is related to the 2 B 2 change of its temperature
• B.4.4 that entropy S is a thermodynamic quantity that relates to the degree of disorder of the particles in a system
• B.4.5 that entropy can be determined in terms of macroscopic quantities such as thermal energy and ΔQ temperature as given by ΔS = and also in terms of the properties of individual particles of the T system as given by S = kB ln Ω where kB is the Boltzmann constant and Ω is the number of possible microstates of the system
• B.4.6 that the second law of thermodynamics refers to the change in entropy of an isolated system and sets constraints on possible physical processes and on the overall evolution of the system
• B.4.7 that processes in real isolated systems are almost always irreversible and consequently the entropy of a real isolated system always increases
• B.4.8 that the entropy of a non-isolated system can decrease locally, but this is compensated by an equal or greater increase of the entropy of the surroundings
• B.4.9 that isovolumetric, isobaric, isothermal and adiabatic processes are obtained by keeping one variable fixed
• B.4.10 that adiabatic processes in monatomic ideal gases can be modelled by the equation as given by 5 PV 3 = constant
• B.4.11 that cyclic gas processes are used to run heat engines
• B.4.12 that a heat engine can respond to different cycles and is characterized by its efficiency as given by useful work η= input energy
• B.4.13 that the Carnot cycle sets a limit for the efficiency of a heat engine at the temperatures of its heat Tc reservoirs as given by ηCarnot = 1– .