Two half cells is an electrochemical cell a salt

This preview shows page 28 - 29 out of 29 pages.

Two half-cells is an electrochemical cell. A salt bridge allows ions to pass while keeping the solutions from mixing. The electromotive force generated by the cell is a measure of the driving force of the chemical reaction occurring in the half-cell solution, ie. a measure of the chemical potential or free energy of the reaction. Joule = measure of electrical energy = energy of flow of 1 ampere in 1 second against an emf of 1 volt = Elt [volt coulomb] OR [joule] Ohm's law is E = IR E = emf [volts] I = current [amperes] R = resistance [ohms] Joule represent work and volts represent force. Amperes are rate of flow of electrons [e / T] or [coulomb/sec] Coulomb is # of electrons per sec (1/96500th of a Faraday) A Faraday is an equivalent of electrons. Some important definitions : energy - the capacity for doing work work - the product of force and the displacement of an object caused by that force. Measured in joules [1N (force) times displacement, meters: Nm]; Newtons are kg m/sec 2 from Weight (force)=mass X acceleration of gravity power - the rate of doing work (units energy per unit time). Some unit expressions describing: Force [mass length/time 2 ] Newtons Energy [force length (displacement)] Btu Calorie Joules kWhr Power [energy/time] Watt Joules/sec Btu/hr Note : Since W = E/time, then kWhr = E it is an E term Power (ie. E/time) : 1 W = 1 J/s = 3.412 BTU/hr Electrical energy expended to change 1 mole of chemical is zEF, where z => is the # of electron-equivalents per mole
Image of page 28

Subscribe to view the full document.

Image of page 29

{[ snackBarMessage ]}

Get FREE access by uploading your study materials

Upload your study materials now and get free access to over 25 million documents.

Upload now for FREE access Or pay now for instant access
Christopher Reinemann
"Before using Course Hero my grade was at 78%. By the end of the semester my grade was at 90%. I could not have done it without all the class material I found."
— Christopher R., University of Rhode Island '15, Course Hero Intern

Ask a question for free

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