Chemistry of Silver Tarnish; Period 3 Will Byun

1. The Chemistry of Silver Tarnish
and its Removal
Will Byun
3rd

2. Intro
▫ Silver tarnish can be
treated in a couple of
ways, including the
usage of simple Silver
Polish Products.
▫ These, however, might
damage the silver, and
is not preferred (Silver
1). Instead, a chemical
reaction with aluminum
can come in handy. https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=
&cad=rja&uact=8&docid=XkkoRd1ejOImsM&tbnid=c-pnv-
1Nb76XpM:&ved=0CAQQjB0&url=http%3A%2F%2Fwww.hermansilver.co
m%2Fcare.htm&ei=OUhoU_7_I6qssQTr-
oDIBQ&bvm=bv.65788261,d.aWc&psig=AFQjCNHq6QDch8UPj4fM2GCG
FhRaC9546g&ust=1399429530077336

3. Formation of Tarnish
• Usually caused by Hydrogen Sulfide, or sulfur in
general. From:
▫ Eggs
▫ Greens
▫ Air 4Ag + 2H2S + O2 → 2Ag2S + 2H2O
https://www.google.com/url?sa=i&rct
=j&q=&esrc=s&source=images&cd=&c
ad=rja&uact=8&docid=So1BXqOQeZv
Q2M&tbnid=0ITw1X2nbeQxEM:&ved
=0CAQQjB0&url=http%3A%2F%2Fw
ww.gizmag.com%2Fsilver-tarnish-
atomic-layer-
desposition%2F26849%2F&ei=4VBoU
-
C_AtPRsATCvoDQAQ&bvm=bv.6578
8261,d.aWc&psig=AFQjCNGEbtiZMw
AW_0E0eWG77bYeK22bdg&ust=1399
431702358576

4. Steps to Chemically Remove Tarnish
• Example video of
demonstration:
▫ Tarnished silver necklace in a
container with aluminum foil,
baking soda (salt), and hot
water
1) Place aluminum foil in the
container so that it covers
the bottom.
2) Put a teaspoon of salt or
baking soda.
3) Pour hot water.
4) Place the tarnished silver so
that it sinks completely.

5. Chemistry Behind the Steps
• 3Ag2S + 2 Al → 6Ag + Al2S3
(Silver 1)
• Because aluminum is more
active than silver, single
replacement reaction occurs.
This equation can be expressed as a redox
equations:
2Al + 6 OH- → Al2O3 + 3H2 O + 6e-
and
Ag2S + 2H2O + 2e- + 2Ag + H2S + 2OH-
The electron flows from aluminum to
silver, making them an anode and a
cathode respectively.

6. Chemistry, Continued
• This means that Aluminum is oxidized and silver
is reduced (Lecture 1-2).
• The boiling water speeds up the reaction because
increased temperature increases the rate of
chemical reaction.
• The salt or baking soda added functions as the
electrolyte, helping the electrons transfer
(Shaw 5).

7. Applications
• Silver is a common element seen in daily life,
from:
▫ Silverware
▫ Jewelry
▫ Coins
▫ Etc.
• These are valuable items, and should be taken
care with effort. To keep silver undamaged, it is
essential to understand this chemical reaction
and its process

8. Citations
• "Lecture Demonstrations - Cleaning Tarnished
Silver." University of
Massachusette Amhers Chemistry. UMassAmherst, n.d.
Web. 3 Apr. 2014.
http://lecturedemos.chem.umass.edu/electrochemistry19_
4.html
• Shaw, David. "Silver Lightning." Chem Matters Dec. 1996: 4-5.
Print.
• "Silver to Black - and Back." Journal of Chemical Education.
ACS, 1 Mar. 2000.
Web. 19 Mar. 2014.
<http://pubs.acs.org/doi/abs/10.1021/ed077p328A>.