Question

Which of the following is/are correct for 1 mole of electrons?
(This question has multiple correct options)
A.$ 6.023\times { 10 }^{ 23 }$ electrons
B.$ 5.48\times { 10 }^{ -7 }Kg$
C.96500 coulomb charge
D.None of these

Answer 1

Hint: Electrons are quantum particles. One mole of electrons is an amount of electrons that has a specific number of electrons present in it, they have a fixed mass along with a fixed charge.

Complete step by step answer:

Before proceeding to solve the above question, we first need to understand the Mole concept. Mole (mol) is used as a unit of measurement for the amount of a substance (element, compound, solvent) in the International System of Units (SI). One mole of a substance has $6.023\times { 10 }^{ 23 }$ (Avogadro number) particles. These particles can be atoms, molecules, ions, or electrons.

The Avogadro number was chosen in such a way that the average mass of one particle in daltons is numerically equal to the mass of one mole of a compound in grams. For example, one mole of Helium contains $6.023\times { 10 }^{ 23 }$ molecules with the total mass of about 4.003 grams and the mean mass of one atom of He is about 4.003 daltons.

The SI unit for the electric charge is coulomb (C). One coulomb refers to the amount of electric charge transported by a steady electric current of one ampere in one second.

The Faraday constant is named after Michael Faraday and is denoted by the symbol F. This constant denotes the amount of electric charge per mole of electrons or the amount of charge carried by one mole of electrons. This can be explained easily. One mole of electrons is equal to the Avogadro number, therefore Faraday constant will be equal to the magnitude of charge present on these 1 mole of electrons.
$F=96485.3C{ mol }^{ -1 }=1.60218\times { 10 }^{ -19 }C/{ e }^{ - }\times 6.023\times { 10 }^{ 23 }{ e }^{ - }/mol$

 We approximate its value as 96500 $ C{ \quad mol }^{ -1 }$ to make calculations easier.
Since, the mass of 1 electron = $ 9.1\times { 10 }^{ -31 }Kg$
Therefore, mass of 1 mole of electron= $ 9.1\times { 10 }^{ -31 }Kg\times 6.023\times { 10 }^{ 23 }=5.48\times { 10 }^{ -7 }Kg$.

Therefore the correct answers are: (a) $ 6.023\times { 10 }^{ 23 }$ electrons, (b)$ 5.48\times { 10 }^{ -7 }Kg$ and (c) 96500 coulomb charge.

Note: Always remember the analogy between the weight of a species in daltons and the weight of that species in grams and how the Avogadro number connects the two with each other.