How Do You Calculate the Number of Electrons in a Mole Using Faraday's Constant?

  • Thread starter Thread starter david2120
  • Start date Start date
  • Tags Tags
    Determination
Click For Summary

Discussion Overview

The discussion revolves around the calculation of the number of electrons in a mole using Faraday's constant, specifically focusing on the charge values provided and the methodology for deriving Avogadro's number from them. The scope includes mathematical reasoning and experimental application.

Discussion Character

  • Mathematical reasoning
  • Experimental/applied
  • Debate/contested

Main Points Raised

  • One participant proposes using the value of 3.407x10^-8 coulombs/mole and the charge of an electron (1.60x10^-19 coulombs) to calculate the number of electrons in a mole.
  • Another participant agrees with the proposed calculation method but does not provide additional context.
  • A different participant questions the origin of the 3.407x10^-8 value and points out that the calculation seems to yield units of [mole^-2], which are considered meaningless.
  • Another participant emphasizes that the calculation incorrectly uses the number of electrons in a mole to determine the number of electrons in a mole, suggesting the problem should focus on how many electrons correspond to the experimentally determined charge.
  • One participant mentions conducting an experiment in class to determine Faraday's constant, resulting in the value of 3.407x10^-8.
  • Another participant asserts that the initial value is off by a factor of 10^12 and reiterates the need to determine how many electrons correspond to the experimentally determined charge.
  • A later reply calculates the number of electrons per mole as 2.12938E^11 by dividing the charge value by the charge of an electron.

Areas of Agreement / Disagreement

Participants express differing views on the validity of the calculation method and the origin of the charge value. There is no consensus on the correctness of the initial charge value or the calculation approach, indicating multiple competing views remain.

Contextual Notes

Limitations include the unclear origin of the charge value 3.407x10^-8 coulombs/mole and the potential misinterpretation of units in the calculations. The discussion does not resolve these issues.

david2120
Messages
15
Reaction score
0
using the number obtained 3.407x10^-8 coulombs/mole and the fact that one electron has a charge of 1.60x10^-19 coulombs, calculate how many electrons there are in one mole (i.e. Avogadro's number)


I am not sure but do you do this problem like this?

3.407x10^-8coulombs/mole x 6.022x10^23electrons/mole divide 1.60x10^-19coulombs
 
Physics news on Phys.org
david2120 said:
3.407x10^-8coulombs/mole x 6.022x10^23electrons/mole divide 1.60x10^-19coulombs

Yep, that looks good to me.

~H
 
david2120 said:
using the number obtained 3.407x10^-8 coulombs/mole and the fact that one electron has a charge of 1.60x10^-19 coulombs, calculate how many electrons there are in one mole (i.e. Avogadro's number)
Please state the entire question - not just a part of it. Where was the number 3.407... obtained from ?

I am not sure but do you do this problem like this?

3.407x10^-8coulombs/mole x 6.022x10^23electrons/mole divide 1.60x10^-19coulombs
That doesn't look right to me (for one thing, it has units of [mole^-2] which are meaningless), but neither does the question as posted.
 
david2120 said:
using the number obtained 3.407x10^-8 coulombs/mole and the fact that one electron has a charge of 1.60x10^-19 coulombs, calculate how many electrons there are in one mole (i.e. Avogadro's number)I am not sure but do you do this problem like this?

3.407x10^-8coulombs/mole x 6.022x10^23electrons/mole divide 1.60x10^-19coulombs
The huge problem here is that you (improperly) used the number of electrons in a mole to determine...the number of electrons in a mole.

The problem basically boils down to "how many electrons does it take to give a charge of 3.407e-8 C.

Again as it was said above, the first given number is a bit suspicious...
 
Last edited:
In Lab I did an experiment in class on trying to determine Faraday's constant and I got 3.407x10^-8 and I have to used that on my calculations
 
Well I hate to break your hopes but you're off by a factor of 1012.

But yes like I said you just want to determine how many electrons it would take to get the charge that you experimentally determined. It's just a simple factor label problem. You are given C/m (Coulombs per mole) and want to determine N/m (number of electrons per mole) given C/N (Charge per electron)
 
Last edited:
oh so its 3.407x10^-8 C/m divide 1.60x10^-19coulombs which equals to

2.12938E^11 N/m (number of electrons per mole)
 

Similar threads

Chemistry How do you calculate moles to neutralise oxalic acid?
  • · Replies 1 ·
Replies
1
Views
2K
Deriving Avogadro's Number without using "mol"
  • · Replies 36 ·
2
Replies
36
Views
7K
Chemistry How Many Moles of Electrons Weigh 1 kg?
  • · Replies 2 ·
Replies
2
Views
3K
Undergrad Number of free conduction electrons in a segment of wire
  • · Replies 2 ·
Replies
2
Views
1K
Chemistry How do we use enthalpy of formation in this calculation?
  • · Replies 9 ·
Replies
9
Views
3K
Chemistry How Do You Calculate Moles in a CaCO3 and HCl Reaction?
  • · Replies 2 ·
Replies
2
Views
3K
How Do You Calculate pH and [OH-] for a Mixed NH3 and NH4Cl Solution?
  • · Replies 1 ·
Replies
1
Views
2K
How Do You Determine Percent Composition in a Gas Mixture Problem?
  • · Replies 4 ·
Replies
4
Views
7K
How Do You Calculate the Partial Pressure of NO2 in a Reaction Using PV = nRT?
  • · Replies 1 ·
Replies
1
Views
7K
Undergrad How Do You Calculate Equilibrium Conditions After Mixing Two Different Gases?
  • · Replies 3 ·
Replies
3
Views
3K