-- The Home Page of the Finishing Industry
Serious Education & the most FUN
you can have in metal finishing smiley

No popups, spam, registration or passwords
on this site
current topics
topic 1120

Cleaning Copper


I am doing a science experiment on Cleaning Copper(pennies). I have found information that states if you mix together orange juice and salt, lemon juice and salt, or Vinegar and salt, it will remove the copper oxide from the surface of the penny. I am now searching for information on what is in these substances that dissolves the copper oxide.

Amanda Heigns
- Marion, Iowa


I am surprised to hear that orange juice plus salt would make an effective copper cleaner, but I haven't tried that one (I've tried the other two many times). I'm not so sure that even your chemistry teacher FULLY understands what makes lemon juice with salt or vinegar with salt an effective cleaner (I don't). But both lemon juice (citric acid) and vinegar (acetic acid) provide mild acids that provide dissolution power for copper oxides, roughly per this equation.

(2H+)(anion--) + Cu++0-- => H20 + (Cu++)(anion--)

The exact role of the chloride ion from the salt is where things get muddy. I believe it provides additional conductivity to assist in ion transport, and the good solubility of copper chloride probably assists as well.

Ted Mooney, Teds signature
Ted Mooney, P.E.
Pine Beach, New Jersey


Well, I haven't used salt of any kind or orange juice, but I have used rice vinegar, lemon juice, and alcohol. My results were more disappointing than had it been normal vinegar that I was using.

Jacqueline Luo
- Houston, Texas

If you have a question in mind which seems off topic, please Search the Site

ADD a Comment to THIS thread START a NEW threadView CURRENT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.