Question

In: Physics

if i understood this correctly, the determination of voltage for a specific voltaic (gallvanic) cell is...

if i understood this correctly, the determination of voltage for a specific voltaic (gallvanic) cell is determined only by the chemical correlation between the two metals. is this true? for an example , if i use iron instead of zinc in the example from wikipedia, i will get a different voltage?

Solutions

Expert Solution

for an example , if i use iron instead of zinc in the example from wikipedia, i will get a different voltage?

Yes.

is determined only by the chemical correlation between the two metals. is this true?

No.

The voltage of a galvanic cell is the sum of the voltages of the "half cells", wich can (not must!) be made from a metal and a solution around that "electrode". Both the metal (or what else is there as "active" material) and the solutions ("electrolyte") quality and concentration determine the voltage of this "electrode".
There are cases, in which there is a single electrolyte for both "electrodes" and where the influence of the electrolyte on both electrodes cancel out. (Eg the oldfashioned acid Zink/Manganese dioxide "dry" cells and the more recent "alkaline" Zink/mangese dioxide cells, both have about 1.5 Volts). But in general, all components have an influence.

PS Be aware that the popular use of "electrodes" (up to physics textbooks!) is wrong. The carbon rod in a Zink/"carbon" cell is not an electrode at all. This is a contact material able to withstand the corrosive environment. The electrode is a mass of manganese dioxide. The latter then is "explained" as "depolarisator", a theory obsolete (and known to be wrong) since Nernsts law was published more than 100 years ago.


Related Solutions

Nickel and aluminum react within a voltaic cell. Calculate the voltage of the standard cell. If...
Nickel and aluminum react within a voltaic cell. Calculate the voltage of the standard cell. If the solutions contain 1.5 M Ni2+ and 0.6 M Al3+, what is the initial voltage?
The cathode in a voltaic cell and in an electrolytic cell is Select one: a. the...
The cathode in a voltaic cell and in an electrolytic cell is Select one: a. the site of oxidation and of reduction, respectively. b. the site of reduction and of oxidation, respectively. c. positive in both cells. d. the site of reduction in both cells. e. the site of oxidation in both cells.
I have a Li-ion cell I need to measure the cell voltage which is unknown. you...
I have a Li-ion cell I need to measure the cell voltage which is unknown. you need to measure the voltage of the battery. You can design the circuit which measures voltage. I need a circuit diagram with explanation. don't say use voltmeter instead you can draw an internal diagram of how it is working.....
What is the difference between an electrochemical cell and a voltaic cell? Is there any? If...
What is the difference between an electrochemical cell and a voltaic cell? Is there any? If they are different how do each of their electrons flow?
If the cell potential for a voltaic cell is 0.250 V, and the reduction potential for...
If the cell potential for a voltaic cell is 0.250 V, and the reduction potential for the oxidation reaction is ⎯0.150 V, what is the reduction potential for the reaction occurring at the cathode?
What is the standard cell potential, E°cell, for the spontaneous voltaic cell made by coupling a...
What is the standard cell potential, E°cell, for the spontaneous voltaic cell made by coupling a Ca+2|Ca (E°red=-2.756V) half-cell and a Al+3|Al (E°red=-1.662V) half-cell? Report your answer in volts, V. Please show where you get the numbers, and write clearly please :)
Consider the electrochemical cell described below: What is the cell potential (Ecell) for the voltaic cell...
Consider the electrochemical cell described below: What is the cell potential (Ecell) for the voltaic cell described below if the. Ag(s) çAg2CrO4 (Sat. Aq. Soln) çç Ag+ (0.125 M) ç Ag(s) a. What is the concentration of [Ag+] in the anode of the cell described above, if the Ksp of Silver (I) chromate is 1.1 x 10-12 ? b. What is the Ecell? c. Draw an overall cell diagram for this cell. Remember to label the cathode, anode, and electron...
A voltaic cell consists of a Pb/Pb2+ half cell and a Cu/Cu2+ half cell at 25C....
A voltaic cell consists of a Pb/Pb2+ half cell and a Cu/Cu2+ half cell at 25C. The initial concentrations of Pb2+ and Cu2+ are 0.0520 M and 0.150 M respectively. Part A: What is the initial cell potential *Write answer using two significant figures Part B: What is the cell potential when the concentration of Cu2+ has fallen to 0.210 M *Write answer using three significant figures Part C: What is the concentration of Pb2+ when the cell potential falls...
A voltaic cell consists of a Pb/Pb2+ half-cell and a Cu/Cu2+ half-cell at 25 ∘C. The...
A voltaic cell consists of a Pb/Pb2+ half-cell and a Cu/Cu2+ half-cell at 25 ∘C. The initial concentrations of Pb2+ and Cu2+ are 5.30×10−2 M and 1.60 M , respectively. Part A What is the initial cell potential? Express your answer using two significant figures. Ecell= ? V Part B What is the cell potential when the concentration of Cu2+ has fallen to 0.230 M ? Express your answer using two significant figures. Part B What is the cell potential...
A voltaic cell consists of a Pb/Pb2+ half-cell and a Cu/Cu2+ half-cell at 25 ∘C. The...
A voltaic cell consists of a Pb/Pb2+ half-cell and a Cu/Cu2+ half-cell at 25 ∘C. The initial concentrations of Pb2+ and Cu2+ are 5.00×10−2 M and 1.70 M, respectively. What is the cell potential when the concentration of Cu2+ has fallen to 0.250 M ? What are the concentrations of Pb2+ and Cu2+ when the cell potential falls to 0.37 V?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT