Standard electrode potentials, chemistry, Microeconomics

Measured cell emf are the basis for standard electrode potentials. chemistry assignments

A method for the presentation of the data obtained from measurements of the equilibrium emf of electrochemical cells must now be developed. One expects (a thermodynamic proof of this is given in the description) that varying the concentration of any reagents involved in the electrode process will affect the emf of the cell. In view of this, the emfs of the cell with the reagents at standard states are reported. In keeping with standard states introduced with these standard state conditions are again chosen to consist of gases at unit activity, implying for most gases approximately 1 bar pressure, and solutes also at unit activity. For solutes, which for electrochemical cells are frequently ions, the activities can be appreciably different from molar concentrations. How activity coefficients can be determined to recognize that a standard state is chosen and that the emf's that cells would have for their variable reagents at unit activity are tabulated.

It is impractical, however, to list the emf's of all possible combinations of electrodes. It would be much more convenient to have some means of tabulating the relative electron accepting powers of the individual electrodes. This can be done by tabulating the emf of cells composed of a selected reference electrode and a variety of other electrodes. Quite arbitrarily, it is agreed that the hydrogen electrode, with a hydrogen pressure of 1 bar and a unit hydrogen ion activity in the solution, will be used as the reference electrode.

Tabulations can then be given of the emf measured for cells with the standard hydrogen electrode on the left and another electrode on the right. For example:

Pt| H2 (1 bar)| HCl (a = 1) | Cl2 (1 bar) | Pt

The emf of this particular cell is found to be + 1.3592 V and it is this value which is given for the Pt| Cl2 |Cl-electrode.

Such tabulated values also are interpreted as electrode emf's based on a zero emf being assigned to the reference hydrogen electrode. If the value is for all reagents at unit activity, such electrode potentials are known as standard electrodes potentials, indicated by the symbol €°. The results for the hydrogen chlorine cell can now be interpreted by recalling that the reported cell emf of +1.3592 V corresponds to the process in which electrons are gained from the external circuit by the right electrode and delivered to the external circuit by the left electrode.  

Posted Date: 2/15/2012 8:18:22 AM | Location : United States







Related Discussions:- Standard electrode potentials, chemistry, Assignment Help, Ask Question on Standard electrode potentials, chemistry, Get Answer, Expert's Help, Standard electrode potentials, chemistry Discussions

Write discussion on Standard electrode potentials, chemistry
Your posts are moderated
Related Questions
Major air pollutants can be sub divided into 2 catexampleories: Inorganic gases and particular gases. (A) Inorganic gases 1. Carbon monoxide (CO) CO is a colourless, lethal gas

At what point is the Fed likely to raise interest rates for the first time? How large are the first couple of hikes likely to be? (hints: conditional on unemployment or gdp growth

Define structural isomers and its types Coordination compounds that having same compositions but the different bonding attachments. Types of structural isomers Hydration isomers

can i get a case study on share market or any other company about their exceptions to the law of demand?

Assume that the U.S. Department of Agriculture (USDA) administers the price floor for cheese, set at $0.17 per pound of cheese. (The price floor is formally set at $16.10 per hundr

write down the assumotions and importance of game theory

We discussed why economists prefer to use available statistics and econometric techniques over other means of measuring consumer demand. Write a short essay describing a situation

Q. Define government surplus? Surplus, Government:It's a government surplus exists when a government's tax revenues surpasses its total spending (including both program spendin

Q. What is Benefits transfer? The process of transferring benefit estimates from past valuation studies to the present study, in order to reduce appraisal costs. The validity

#question. what is the underlying reason for the law of increasing opportunity cost?