Carnot Engines, Efficiency, and The Second Law

Carnot Engines, Efficiency, and The Second Law - Carnot...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Carnot Engines, Efficiency, and The Second Law Chemistry 213 Fig. 1. The Carnot Cycle The Carnot engine is a useful construction for relating the mathematical ( S 0 for a spontaneous process in an isolated system) and the physical statements of the Second Law of Thermodynamics (heat spontaneously flows from hot to cold). This handout goes through the analysis of the amounts of work and heat produced in the isothermal and adiabatic parts of the Carnot cycle for an ideal gas. 1. Energy in an Ideal Gas: Joule’s Experiment In his study of the thermal properties of gases, Joule considerer the isothermal expansion of dilute gases using the apparatus depicted below: Winter Term 2001-2002
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Second Law of Thermodynamics -2- Chemistry CHEM 213W P=0 Thermometer P=0 / Fig. 2. Joule’s Experiment The bulb on the right was evacuated initially and heat was allowed to exchange with the heat bath, whose temperature was measured. For sufficiently dilute gases, Joule found that the tem- perature of the bath didn’t change. This has some important consequences. For this process, P op = 0, and hence, W = 0. Moreover, since the temperature of the bath remained constant, no heat was absorbed by the system, and thus E = 0. What does this say about the functional form of the energy of an ideal gas? We know that we can write the energy of a one-component system as E ( N , V , T ) = N E ( T , N / V ), where density was chosen instead of pressure as an independent variable (as can always be done if the equation of state is known). In Joule’s experiment T and N were held fixed but V, and
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern