In the electrolysis of copper II tetraoxosulphate VI solution using platinum electrode, 56cm of oxygen measured at stp are collected. Calculate the mass of copper deposited at the same time(Cu-64, molar volume at stp - 22.4 dm)?

YaKhaleed3698

4 years ago

BASIC ELECTROLYSIS CALCULATIONS


The Faraday constant

The Faraday constant is the single most important bit of information in electrolysis calculations. Make sure you really understand the next bit.


Coulombs

The coulomb is a measure of the quantity of electricity. If a current of 1 amp flows for 1 second, then 1 coulomb of electricity has passed.

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.

Number of coulombs = current in amps x time in seconds

If you are given a time in minutes or hours or days, then you must convert that into seconds before you do anything else.

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!


The Faraday

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