Chapter 19 - chemical thermodynamics - outline 5-7-00

In simple terms a process is spontaneous if it

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

the Second Law.  In simple terms  a process is spontaneous if it proceeds on its own once initiated.  In more technical terms,  a process is spontaneous if it transfers  free energy  from the system to the  surroundings.   In 1875 J. Willard Gibbs defined the spontaneity of a reaction in terms of its ability to perform "useful work" (in  principle or practice). This ability to do work is determined, according to Gibbs, by the change in  free energy  during a chemical change,  G . This quantity gives the maximum  amount of work obtainable from a spontaneous  reaction (OR it tells how much work must be done to make a reaction spontaneous).  The sign of  G in an indicator of whether a reaction will be spontaneous or not.  when  G < 0, the reaction is spontaneous in the forward direction(it is capable of doing useful work)  when  G = 0, the system is at equilibrium  when  G > 0, the reaction is non-spontaneous (work must come from the surroundings to make the  reaction happen)   the opposite is true for the reverse reactions…. H represents the total amount of energy that must be transferred to the surroundings in order to keep the temperature of the system at 298 K ** (25 O C = standard temp. for equilibria)
Image of page 1

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

Chemical Thermodynamics
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