From which solution 2 Faraday electrical charge will deposit 1 gram atomic weight at cathode.
Answers
Explanation:
Electricity is a flow of electrons. For calculation purposes, we need to know how to relate the number of moles of electrons which flow to the measured quantity of electricity.
The charge that each electron carries is 1.60 x 10-19 coulombs. If you ever needed to use it in an exam, you would be given the value.
1 mole of electrons contains the Avogadro constant, L, electrons - that is 6.02 x 1023 electrons. You would also be given that in an exam if you needed to use it.
That means the 1 mole of electrons must carry
6.02 x 1023 x 1.60 x 10-19 coulombs
= 96320 coulombs
This value is known as the Faraday constant.
You may come across the formula F = Le, where F is the Faraday constant, L is the Avogadro constant and e is the charge on an electron (in terms of the number of coulombs it carries). We have just used that without actually stating it - it is basically obvious!
The numbers we are using here are rounded off. The calculation just shows you how to work it out if you have to, but doesn't give the normally-used value. For exam purposes, the value of the Faraday constant is usually taken as 9.65 x 104 C mol-1 (coulombs per mole). This is another number you are unlikely to have to remember.
That is 96500 coulombs per mole.
So 96500 coulombs is called 1 faraday. Notice the small "f" when it is used as a unit.
Whenever you have an equation in which you have 1 mole of electrons, that is represented in an electrical circuit by 1 faraday of electricity - in other words, by 96500 coulombs.