{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

# Lecture 7 - A positive voltage means the reaction proceeds...

This preview shows page 1. Sign up to view the full content.

Redox reactions that give max voltage are choosing reactions between elements that are willing to give up electrons and elements that aren’t but are willing to accept electrons. When you examine a periodic table, you will find that (excluding the noble gases) the electronegativity values tend to increase as you go to the right and up. The reverse statement is that the values tend to decrease going down and to the left. This pattern will help when you are asked to put several bonds in order from most to least ionic without using the values themselves Reversing reaction will change sign of standard potential. Always write as reduction though… Multiplying a reaction by a coefficient does not change the free energy (i.e. the standard voltage)
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: A positive voltage means the reaction proceeds forward (as written). Negative means reverse reaction is spontaneous. Charge (uphill direction, negative voltage) and discharge (downhill, positive voltage) dG=(-1)nF(dE) n=number mole electrion, F=Faraday constant (96485.3365 Coulombs/mole), dE=potential In a battery, the more use will build up the Zn+2 concentration on the anode side, and reduce the Cu+2 concentration on the cathode side, slowing down the potential. If you put the zinc anode in the copper solution, voltage will still be produced, it just won’t be captured. Copper will build up on zinc anode… the electrons go straight from zinc to the copper building up on it....
View Full 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