Summary for vinegar and salt plating Discussion
Vinegar and salt are used in the plating experiments because they are safer for students, not because they are the best chemistry for dissolving copper. In response to Cameron F. Kennedy, the answerer explains that hydrochloric acid is not appropriate for middle school and warns that mixing anything with bleach or chlorine tablets is dangerous. He also suggests writing vinegar as CH3COOH rather than C2H4O2 so its ionization in water is clearer, and describes vinegar as ionizing into H+ and CH3COO- while salt ionizes into Na+ and Cl-. When Cameron later asks about the copper chemistry, the answerer adds that copper sulfate (CuSO4·5H2O) plus sulfuric acid is the relevant combination. The thread does not endorse making HCl from chlorine tablets or using it for this classroom-style plating setup.
Q. Hi,
I have read a lot of these articles about plating coins and keys and such. This article on your website
(www.finishing.com/faqs/plating.shtml) says that vinegar
⇦ in bulk on
or
Amazon [affil link] cannot dissolve copper very well. I was wondering if using HCl as an acid for such a plating would work for copper?
Also, just checking, but I believe that to create HCl you mix Chlorine with Water. My question about this is if I let a chlorine tablet dissolve in water will this create the HCl and HClO mix or not?
Third Question. Its a bit off topic but I am trying to figure out what the chemical composition of vinegar plus salt creates, vinegar being basically C2H4O2, + NaCl. Do you know what it creates? I have been looking yet I have been unsuccessful
Thanks a lot for your help
Cameron F.
Kennedy Middle School – Cupertino, California, United States
2007
A. Hi Cameron. Our reason for putting those experiments on line with vinegar and salt as the reagents is because they are safe for students. Hydrochloric acid is not appropriate for middle school, and mixing anything with bleach or chlorine tablets is quite dangerous.
In trying to work your way through the formulas, I suggest that you not write acetic acid (vinegar) as C2H4O2 because — although it’s not wrong — it obscures the way that vinegar will ionize in water. Please write it as CH3COOH. Precisely how it ionizes is beyond my grade level, and perhaps yours, but we can probably think of it as ionizing into H+ and CH3COO-, while the salt ionizes into Na+ and Cl-.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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I am not actually in Middle school. That is an automatic fill in thing that I didn’t notice was on. I am in my 2nd year in college. Thanks about the vinegar. I actually found that out just a day after I posted that. Thanks for your help.
Thanks,
Cameron F. [returning]
– Cupertino, California, United States
A. Hi again Cameron.
Copper sulphate (CuSO4·5H20) plus sulfuric acid
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.