Re: How does vinegar react with silver plated utensils?

Pure (?) vinegar should be a solution (~5%) of acetic acid in water.  
Silver does not react with water.  Because of silver's low reactivity and 
the weak nature of acetic acid, I would not expect any reaction here 
either.  It is well known that silver (plate or otherwise) reacts with 
sulfur compounds, those found in the air (hydrogen sulfide, sulfur dioxide, 
etc.), to form the dark color of the tarnish.  It is also known that the 
sulfur in proteins can cause similar tarnish on silver.  Eggs are a 
particularly good source of this type of tarnish.  I would wonder about 
what minor (sulfur containing?)contaminants might be in the vinegar used in 
this case.  The food that may have been in the container used for the 
vinegar may be a source.  These are my best guesses.  Yes, there is an 
electrochemical angle to all of this since the silver is losing electrons 
to become the silver ion in the tarnish compounds. 

Sorry that it took me a while to get you this answer.

Jerry Franzen
Chemistry Department
Thomas More College
333 Thomas More Pkwy.
Crestview Hills, KY 41017
606-344-3377