What is Gibbs free energy? What is the difference between entropy and enthalpy? What does the useful work derived do such that the entropy increases (additional to that increased along with enthalpy) but enthalpy remains the same (i.e the useful work does not increase the enthalpy)?© BrainMass Inc. brainmass.com October 16, 2018, 4:43 pm ad1c9bdddf
Understanding Gibbs Free Energy Change Qualitatively
Gibbs free energy is a measure of the spontaneity of a reaction. Basically, a process that can occur under a particular set of conditions is said to be spontaneous; a process that cannot occur under the given conditions is nonspontaneous.
Although a reaction may be spontaneous, it may not occur at an observable rate. The speed of a reaction involves kinetics, not thermodynamics. Gibbs free energy is not a kinetic term, it is a thermodynamic term.
Kinetics is related to the "activation energy" of a reaction, i.e. the amount of energy required to move the reactants "up the energy hill" to the ...
Gibbs free energy change is analyzed. The differences between entropy and enthalpy are found.
Gibbs free energy and chemical potential
Focus Question: Consider a sample of CaO(s) at 298K and 1 atm. Does the Gibbs energy of the sample increase, decrease of remain the same if the temperature is raised to 350K? Does the Gibbs energy of the original sample increase, decrease of remain the same if the pressure is increased to 2 atm?
1. For a constant temperature process what is the relationship between dG, V and p?
2. Using the equation you have derived in 1 solve for a relationship between ∆G and ∆p assuming that V and T are constant.
3. Use the ideal gas law to obtain a relationship between ∆G and ∆p for n moles of an ideal gas at constant T and V.
4. Using 3 and 3the definition of chemical potential above to obtain a relationship between μ p and T.
5. How does the chemical potential change as the temperature and pressure are increased?