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Vinegar+bleach+salt to Pit Pennies Rapidly [Canada] 

March 7, 2008

I have been trying for years to find an answer to this question:
It started when I was a kid and I was experimenting with household chemicals (not recommended) and a penny. I tried different combinations and found that Vinegar, Salt, and Bleach combined make an extremely corrosive agent against the penny. In moments of combining all three the penny will turn green. After being left for only a number of hours, the penny was almost beyond recognition. The chemical mixture turned brown and the penny had small pits in it wherever there had been a grain of salt sitting on it or under it.
I have tried to find an answer all over. This site was the closest thing. I found some stuff for Vinegar+Bleach solutions but none for the additional salt. I've found that the reaction I've been experiencing only happens when all three components are combined. If any one is missing the results won't happen or they will not be nearly as dramatic or quick.
Thanks

Jaron Willems
- Rycroft, Alberta, Canada

I understood your description, Jaron, but I didn't hear a question. What is your question? Note: mixing bleach and vinegar is horribly dangerous. The reason it's so corrosive is the instantaneous release of large quantities of poisonous chlorine gas (as well as oxygen).

Ted Mooney, P.E.  finishing.com Brick, NJ

Sorry, I got so much into the experiments I've done that I forgot my question.

I wanted to know why that combination (Bleach, Vinegar, and Salt) reacts so quickly with pennies (copper).

I was also wondering if the resultant mixture was a special chemical.

What kind of chemical reaction is happening?

Your information about the chlorine gas was very good. Just a note: I ALWAYS do this outside or at least in a well ventilated area and I never stand or put my face directly over the chemicals.

Thanks for your response.

I appreciate hearing from someone who knows what they are talking about and not just another kook on the web.

Jaron Willems
- Rycroft, AB, Canada

Hi, again. Bleach is sodium hypochlorite (NaOCl) with caustic soda (NaOH) added to lower the pH of the solution to help keep the chlorine gas dissolved in the water. When anything acidic like vinegar is added, large amounts of chlorine gas are quickly released. The chemistry of the reaction is explained at www.chemistryquestion.com/English/Questions/ChemistryInDailyLife/3c_bleach_cleaner.html

The chlorine gas is an extremely powerful oxidizing agent that corrodes copper rapidly.

Regards,

Ted Mooney, P.E. 
finishing.com
Brick, NJ