Entropy and Gibbs free energy

Discussion in 'MCAT Study Question Q&A' started by Hemichordate, 07.11.10.

  1. SDN is made possible through member donations, sponsorships, and our volunteers. Learn about SDN's nonprofit mission.
  1. Hemichordate

    Hemichordate Peds 7+ Year Member

    Joined:
    05.05.08
    Messages:
    1,082
    Status:
    Resident [Any Field]

    SDN Members don't see this ad. About the ads.
    If entropy dictates the direction of a reaction, do enthalpy and gibbs free energy dictates how fast the reaction proceeds in that direction?
     
  2. SDN Members don't see this ad. About the ads.
  3. loveoforganic

    loveoforganic -Account Deactivated- 2+ Year Member

    Joined:
    01.30.09
    Messages:
    4,225
    I think you're a bit confused, but I may just be misunderstanding what you're asking.

    Changes in entropy and enthalpy are the two factors (along with temperature) that give you your gibbs free energy change for a given reaction (the favorability of a reaction). This is generally referred to as the thermodynamics of a reaction.

    The rate of reaction is determined by the order of the reaction, the temperature, and the activation energy of the reaction. This is generally referred to as the kinetics of a reactions.

    There is not necessarily a relationship between favorability and rate.
     
  4. Hemichordate

    Hemichordate Peds 7+ Year Member

    Joined:
    05.05.08
    Messages:
    1,082
    Status:
    Resident [Any Field]
    I guess I'm just wondering if entropy is the sole factor that usually determines the direction of a reaction.
     
  5. RogueUnicorn

    RogueUnicorn rawr. 5+ Year Member

    Joined:
    07.15.09
    Messages:
    9,493
    Status:
    Resident [Any Field]
    no gibbs free energy is.
     
  6. loveoforganic

    loveoforganic -Account Deactivated- 2+ Year Member

    Joined:
    01.30.09
    Messages:
    4,225
    This. dG = dH - TdS

    Your dG value ultimately tells you the favorability of a reaction.

    dH, T, and dS are factors that tell you your dG value.
     

About the ads

Share This Page