How can an electroplating circuit function as a current measuring device?

Question

How can an electroplating circuit function as a current measuring device?

Answer 1

By measuring the amount of material plated in a time interval. From that you can calculate the charge and the current.

Answer 2

Any freshman chem. book will contain an example, but consider this paragraph...

Students should be introduced to Faraday's law before doing this experiment. From this law, students will note that 2 x 96,485 coulombs of charge are required to produce one mole of copper from copper(II) ion. If an ammeter reading is taken, the number of coulombs that actually passed through the electrolytic cell can be calculated by using the formula; q = It, where q is the charge in coulombs, I is the current in amperes, and t is the time in seconds. From the coulombs of charge that pass through the cell, students can calculate the theoretical number of moles of copper that should have plated out and compare this to the actual number of moles that were plated out. If one assumes that the theoretical yield is equal to the actual yield, the atomic mass of copper can be calculated.

from this site:

http://www.woodrow.org/teachers/chemistr...

If you don't measure the current but DO measure the amount of copper you plate, you will find the amps that flowed through the cell.  Because mass of metal plated (the number of electrons required for the reaction depends on the metal--so be careful) and the current are related, one needs to know only one to find the other.

Hope that helps a bit.