{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lec 28 March 16 Mon

# Lec 28 March 16 Mon - 3.19 D Non-standard free energy(Sect...

This preview shows pages 1–2. Sign up to view the full content.

3.19 D. Non-standard free energy (Sect. 19-6) (when you no longer have 1atm/1M conditions) -- Δ G o is the driving force of a reaction done at standard pressure or concentration conditions (not necessarily at 25 ºC) -- but relative amounts of reactants or products could also drive a reaction (remember LeChatelier’s Principle) -- so non-standard Δ G depends on Δ G o and concentrations For non-standard conditions, now use : Δ G = Δ Gº + RT ln Q 1. If Q < K rxn Δ G < 0 2. If Q > K rxn Δ G > 0 3. If Q = K Δ G = 0 Therefore, when P 1 atm and conc 1 M at equilibrium: Δ G = 0 = Δ Gº + RT ln Q and Q = K at eq. Δ Gº = – RT ln K • The equilibrium constant for a reaction is related to the change in standard free energy. (Remember K has concentrations divided by 1 M so that K has no units) • If you know the equilibrium constant, you now have a third way of determining Δ , and this way is good for any temperature. • When a reaction is at equilibrium, usually Δ 0 because usually [] eq 1 M. For reactions, generally, K 1. When is Δ Gº = 0 ? Only when there is equilibrium when products and reactants are both under standard conditions (e.g. finding phase transition at 1 atm)

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• 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.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• 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.

Dana University of Pennsylvania ‘17, Course Hero Intern

• 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.

Jill Tulane University ‘16, Course Hero Intern