Explore BrainMass

Understanding Gibbs Free Energy Change

This content was STOLEN from BrainMass.com - View the original, and get the already-completed solution here!

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 24, 2018, 6:12 pm ad1c9bdddf

Solution Preview

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 ...

Solution Summary

Gibbs free energy change is analyzed. The differences between entropy and enthalpy are found.

See Also This Related BrainMass Solution

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?
Important formula

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?

View Full Posting Details