Video Transcript
Which of the following best defines
the Faraday constant, 𝐹? (A) The amount of charge per mole
of elementary charge. (B) The number of electrons per
mole of elementary charge. (C) The mass of substance deposited
at an electrode per coulomb of charge. (D) The time taken to deliver one
mole of electrons at an electrode. Or (E) the flow of electric charge
per second.
Say we have electrons traveling
through a wire. We may know how much charge
traveled through the circuit. But we want to know how many
electrons were responsible for that charge. Faraday’s constant allows us to
convert between these two quantities. Mathematically, Faraday’s constant
has a value equal to Avogadro’s number multiplied by the elementary charge. Avogadro’s constant has a value of
6.022 times 10 to the 23 entities per mole. In this case, the entities are
charged particles. Now what is the elementary
charge?
Well, the proton has a charge of
1.602 times 10 to the negative 19 coulombs. This quantity of charge is called
the elementary charge. Of course, the charge of the
electron is exactly the opposite of the charge of the proton. So we can use the elementary charge
in calculations involving the electron as well.
So, if we multiply Avogadro’s
constant by the value of the elementary charge, we’ll be able to calculate Faraday’s
constant, which we can calculate to be 96,472.4 coulombs per mole, using these
rounded values. Usually, a rounded value of 96,500
columns per mole is used in calculations. So there’s about 96,500 coulombs of
charge per mole of elementary charges. This matches answer choice (A). In other words, for every one mole
of elementary charge transferred in a circuit, there are 96,500 coulombs of charge
transferred.
So the statement that best defines
Faraday’s constant is statement (A), the amount of charge per mole of elementary
charges.
