Why Is the Potential of the Hydrogen Electrode Not Zero?

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SUMMARY

The discussion centers on the confusion surrounding the standard potential of the hydrogen electrode, which is often assumed to be zero volts. However, the standard hydrogen electrode (SHE) serves as a reference point, and its potential can vary based on the conditions of the solution, such as molarity. The standard potential is defined as the energy per unit charge available from oxidation/reduction reactions relative to the SHE. Therefore, the potential of the hydrogen electrode can indeed be non-zero, leading to the conclusion that the answer to the posed question is option D.

PREREQUISITES
  • Understanding of electrochemistry concepts, specifically standard electrode potentials.
  • Familiarity with the standard hydrogen electrode (SHE) and its role in electrochemical cells.
  • Knowledge of oxidation/reduction reactions and their energy implications.
  • Basic grasp of solution chemistry, including molarity and its effects on electrode potentials.
NEXT STEPS
  • Research the Nernst equation and its application in calculating electrode potentials under non-standard conditions.
  • Study the principles of electrochemical cells and how different electrodes interact with the SHE.
  • Explore the concept of standard state conditions in thermodynamics and their relevance to electrochemistry.
  • Learn about the various types of electrodes and their standard potentials in different chemical environments.
USEFUL FOR

Students and professionals in chemistry, particularly those studying electrochemistry, as well as educators seeking to clarify the concept of standard potentials in relation to the hydrogen electrode.

TT0
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Homework Statement


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Homework Equations

The Attempt at a Solution


From the calculation of the potential of the cell and the potential for the copper electrode, it states that the hydrogen electrode has a potential of -0.09 V. But I thought hydrogen electrode is standard so it should be zero. Therefore I am not sure between C and D. Can someone explain which one is right and why?

Cheers!
 
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TT0 said:
But I thought hydrogen electrode is standard so it should be zero.

What does it mean "standard electrode"? What does it mean "standard potential"?
 
Standard electrode is a standard hydrogen electrode. Standard potential is the difference in voltage between the standard hydrogen electrode and the concerning electrode. I guess the hydrogen electrode could be non standard as you don't know it's solution's molarity and what M is. This means the answer is D?

Cheers!
 
TT0 said:
Standard electrode is a standard hydrogen electrode. Standard potential is the difference in voltage between the standard hydrogen electrode and the concerning electrode.

"Standard is a standard" is a tautology and it doesn't add much to the problem.

What is the definition of the standard potential?

Actually it seems like you are aware of what is important here, but you failed to mention it correctly.
 
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What is the definition of the standard potential?
I am not too sure. I think standard potential is the reducing strengths of the other electrodes relative to the standard hydrogen electrode.
 
TT0 said:
I am not too sure.

Then google it, or check your notes, or the book.
 
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Standard potential is the measure of the energy per unit charge which is available from the oxidation/reduction reactions of each electrode relative to the standard hydrogen electrode. So as the hydrogen electrode is not the standard one, it's reduction potential can be non-zero so D is the answer?

Cheers!
 
Sadly, this definition doesn't touch on a very important point - standard potential requires the system to be in the standard state.
 
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I see, thanks!
 

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