This statement deals with the Faraday constant. Before you go on, you should find and read the statement in your copy of the syllabus.
The That means that you can work out how much electricity has passed in a given time by multiplying the current in amps by the time in seconds.
If you are given a time in minutes or hours or days, then you For example, if a current of 2 amps flows for an hour, then: Number of coulombs = 2 x 60 x 60 = 7200 (60 minutes in each hour; 60 seconds in each minute.) That's easy!
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 1 mole of electrons contains the Avogadro constant, L, electrons - that is 6.02 x 10 That means the 1 mole of electrons must carry
This value is known as the Faraday constant. You will see that the syllabus statement quotes the formula 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, and in the Data Booklet, the value of the Faraday constant is given as 9.65 x 10 That is 9.65 x 10 So 96500 coulombs is called 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. To return to the list of learning outcomes in Section 6 To return to the list of all the CIE sections This will take you to the main part of Chemguide.
© Jim Clark 2011 (last modified April 2014) |