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Quantitative electrolysis of aqueous copper(II) sulfate

Description

This demonstration is designed to find the value of the Faraday constant. The amount of electric charge carried by one mole of electrons. This will be done with the electrolysis of aqueous copper(II) sulfate and weighed copper electrodes.
quantitative-electrolysis...



Apparatus Chemicals

Eye protection

Access to a fume cupboard

Beaker (250 cm3)

Beaker (100 or 150 cm3)

DC power pack

Connecting leads, including two fitted with crocodile clips, 3

Ammeter, preferably digital and a demonstration model

Rheostat

Switch

Stop clock

Balance (weighing to +/-0.01 g)

Hot-air blower, such as a hair drier

Emery paper

Paper towels or tissues

Copper foil electrodes, 2 (Note 1)

Copper(II) sulfate solution, about 1.0 M (HARMFUL), 200 cm3

Propanone (HIGHLY FLAMMABLE, IRRITANT), about 200 cm3

Refer to Health & Safety and Technical notes section below for additional information.

 


Read our standard health & safety guidance


Mass of cathode (-) before /g  
Mass of cathode (-) after /g  
Change in cathode's mass /g  
Mass of anode (+) before /g  
Mass of anode (+) after /g  
Change in anode's mass /g  
Current used /A  
Time for electrolysis /s  

 


student worksheet 



This demonstration is designed to find the value of the Faraday constant. The amount of electric charge carried by one mole of electrons. This will be done with the electrolysis of aqueous copper(II) sulfate and weighed copper electrodes.

ADDITIONAL INFORMATION

This is a resource from the Practical Chemistry project, developed by the Nuffield Foundation and the Royal Society of Chemistry. This collection of over 200 practical activities demonstrates a wide range of chemical concepts and processes. Each activity contains comprehensive information for teachers and technicians, including full technical notes and step-by-step procedures. Practical Chemistry activities accompany Practical Physics and Practical Biology.