The process of measurement of the charge involved in a process is called coulometry. one of the very accurate methords of coulometry is based on the measurement of the mass of products formed at the anode or the cathode electrolytic cell.
Experimental method and calculations
Example 01
calculate the mass of copper deposited on the cathode when a solution of cuso4 is electrolyzed for 20.0 s with a 2.0 a electric current. [atomic mass of cu = 63.5gmol]
Answer
First I give you a formula that not familiar for advanced level students because it is not in A/L chemistry syllabus it will help you to solved questions easily and quickly in exams.
calculate the mass of copper deposited on the cathode when a solution of cuso4 is electrolyzed for 20.0 s with a 2.0 a electric current. [atomic mass of cu = 63.5gmol]
Answer
First I give you a formula that not familiar for advanced level students because it is not in A/L chemistry syllabus it will help you to solved questions easily and quickly in exams.
m = Q/F *1/Z * M = QM/FZ
Q = mFZ/M
now we can solved the question using that formula
Q = mFZ/M
Where,
m = mass of the ions discharged
Q = charge passed through the solutions
F = faraday constant
Z = charge number of the ions discharged
M = molar mass of the ion
m = mass of the ions discharged
Q = charge passed through the solutions
F = faraday constant
Z = charge number of the ions discharged
M = molar mass of the ion
now we can solved the question using that formula
Q = mFZ/M
m = QM/FZ
Q =It
m = ItM/FZ
m = 2.0 A *20.0 S *63.5 gmol^-1 /96500 C * 2
m = 0.01316 g
m = QM/FZ
Q =It
m = ItM/FZ
m = 2.0 A *20.0 S *63.5 gmol^-1 /96500 C * 2
m = 0.01316 g
I hope that clarifications are helpful for you.