
4-Energy Analysis of Closed Systems
... Electric Heating of a Gas at Constant Pressure • A piston-cylinder device contains 25 g of saturated water vapor that is maintained at a constant pressure of 300 kPa. A resistance heater within the cylinder is turned on and passes a current of 0.2 A for 5 min from a 120-V source. At the same time, ...
... Electric Heating of a Gas at Constant Pressure • A piston-cylinder device contains 25 g of saturated water vapor that is maintained at a constant pressure of 300 kPa. A resistance heater within the cylinder is turned on and passes a current of 0.2 A for 5 min from a 120-V source. At the same time, ...
Momentum Heat Mass Transfer
... Remark: Confusion exists due to definition of the internal energy itself. In some books the energy associated with phase changes and chemical reactions is included into the production term Q(g) (see textbook Sestak et al on transport phenomena) and therefore the energy related to intermolecular and ...
... Remark: Confusion exists due to definition of the internal energy itself. In some books the energy associated with phase changes and chemical reactions is included into the production term Q(g) (see textbook Sestak et al on transport phenomena) and therefore the energy related to intermolecular and ...
• Thermodynamics, what is it? • System, Surrounding and Boundary
... A pure substance can exist in more than one phase, but its chemical composition must be the same in each phase. For example, if liquid water and water vapor form a system with two phases, the system can be regarded as a pure substance because each phase has the same composition. The nature of phases ...
... A pure substance can exist in more than one phase, but its chemical composition must be the same in each phase. For example, if liquid water and water vapor form a system with two phases, the system can be regarded as a pure substance because each phase has the same composition. The nature of phases ...
The Ideal Gas Law and the Kinetic Theory of Gasses
... temperature process. For a process to be isothermal, any heat flow into or out of the system must occur slowly enough that the thermal equilibrium is maintained. In general, none of the three quantities are zero. We can see all these processes on a pV diagram: ...
... temperature process. For a process to be isothermal, any heat flow into or out of the system must occur slowly enough that the thermal equilibrium is maintained. In general, none of the three quantities are zero. We can see all these processes on a pV diagram: ...
Energy
... – All the energy contained within a chemical system – The sum of the kinetic and potential energies of all the “particles” in the system – An increase in the internal energy of a system can take three forms • An increase in temperature • A phase change • The initiation of a chemical reaction – A dec ...
... – All the energy contained within a chemical system – The sum of the kinetic and potential energies of all the “particles” in the system – An increase in the internal energy of a system can take three forms • An increase in temperature • A phase change • The initiation of a chemical reaction – A dec ...
Principle of minimum Energy The second law of thermodynamics
... The system plus the reservoir are considered to be isolated from the rest of the universe. For the system plus the reservoir it must always be: dStotal = dS system + dS ...
... The system plus the reservoir are considered to be isolated from the rest of the universe. For the system plus the reservoir it must always be: dStotal = dS system + dS ...
On Quantizing an Ideal Monatomic Gas
... assumptions about the statistical of the gas molecules as is possible. In recent times, numerous attempts have been made to determine the equation of state of a perfect gas. The equations of state of the various authors and ours differ from each other and from the classical equation of state P V = N ...
... assumptions about the statistical of the gas molecules as is possible. In recent times, numerous attempts have been made to determine the equation of state of a perfect gas. The equations of state of the various authors and ours differ from each other and from the classical equation of state P V = N ...
3.3 and 3.4 Non Flow Energy
... necessary, therefore, that before we start any analysis we define the system that we are looking at. To do this we construct an imaginary boundary around what we are interested in – for example, the cricket ball (struck by Nasser Hussein) or the water in the kettle). When dealing with a non-flow sit ...
... necessary, therefore, that before we start any analysis we define the system that we are looking at. To do this we construct an imaginary boundary around what we are interested in – for example, the cricket ball (struck by Nasser Hussein) or the water in the kettle). When dealing with a non-flow sit ...
Notes in pdf format
... W = nRT ln(Vf/Vi) = (2 mol) [8.31 J/(mol K)] (298 K) ln(0.050 m3/0.025 m3) = 3400 J (b) The internal energy of a monatomic ideal gas i U = 3/2nRT and does not change when the temperature is constant, therefore ΔU = 0 J (c) The heat Q supplied can be determined from the first law of thermodynamics: Q ...
... W = nRT ln(Vf/Vi) = (2 mol) [8.31 J/(mol K)] (298 K) ln(0.050 m3/0.025 m3) = 3400 J (b) The internal energy of a monatomic ideal gas i U = 3/2nRT and does not change when the temperature is constant, therefore ΔU = 0 J (c) The heat Q supplied can be determined from the first law of thermodynamics: Q ...
Blank Jeopardy - prettygoodphysics
... An ideal gas is made up of N diatomic molecules, each of mass M. All of the following statements about this gas are true EXCEPT: (A) The temperature of the gas is proportional to the average translational kinetic energy of the molecules. (B) All of the molecules have the same speed. (C) The molecul ...
... An ideal gas is made up of N diatomic molecules, each of mass M. All of the following statements about this gas are true EXCEPT: (A) The temperature of the gas is proportional to the average translational kinetic energy of the molecules. (B) All of the molecules have the same speed. (C) The molecul ...
Chapter 3: THERMODYNAMICS
... For the special case of a gas to which Boyle's law applies, the product pV is a constant if the gas is kept at isothermal conditions. The value of the constant is nRT, where n is the number of moles of gas present and R is the ideal gas constant. In other words, the ideal gas law pV = nRT applies. ...
... For the special case of a gas to which Boyle's law applies, the product pV is a constant if the gas is kept at isothermal conditions. The value of the constant is nRT, where n is the number of moles of gas present and R is the ideal gas constant. In other words, the ideal gas law pV = nRT applies. ...
Equipartition theorem

In classical statistical mechanics, the equipartition theorem is a general formula that relates the temperature of a system with its average energies. The equipartition theorem is also known as the law of equipartition, equipartition of energy, or simply equipartition. The original idea of equipartition was that, in thermal equilibrium, energy is shared equally among all of its various forms; for example, the average kinetic energy per degree of freedom in the translational motion of a molecule should equal that of its rotational motions.The equipartition theorem makes quantitative predictions. Like the virial theorem, it gives the total average kinetic and potential energies for a system at a given temperature, from which the system's heat capacity can be computed. However, equipartition also gives the average values of individual components of the energy, such as the kinetic energy of a particular particle or the potential energy of a single spring. For example, it predicts that every atom in a monatomic ideal gas has an average kinetic energy of (3/2)kBT in thermal equilibrium, where kB is the Boltzmann constant and T is the (thermodynamic) temperature. More generally, it can be applied to any classical system in thermal equilibrium, no matter how complicated. The equipartition theorem can be used to derive the ideal gas law, and the Dulong–Petit law for the specific heat capacities of solids. It can also be used to predict the properties of stars, even white dwarfs and neutron stars, since it holds even when relativistic effects are considered.Although the equipartition theorem makes very accurate predictions in certain conditions, it becomes inaccurate when quantum effects are significant, such as at low temperatures. When the thermal energy kBT is smaller than the quantum energy spacing in a particular degree of freedom, the average energy and heat capacity of this degree of freedom are less than the values predicted by equipartition. Such a degree of freedom is said to be ""frozen out"" when the thermal energy is much smaller than this spacing. For example, the heat capacity of a solid decreases at low temperatures as various types of motion become frozen out, rather than remaining constant as predicted by equipartition. Such decreases in heat capacity were among the first signs to physicists of the 19th century that classical physics was incorrect and that a new, more subtle, scientific model was required. Along with other evidence, equipartition's failure to model black-body radiation—also known as the ultraviolet catastrophe—led Max Planck to suggest that energy in the oscillators in an object, which emit light, were quantized, a revolutionary hypothesis that spurred the development of quantum mechanics and quantum field theory.