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12/17 Redox Reactions
Leave your completed Precipitates Lab out to be collected.
They will be graded in the exhibition category.
1. Make qualitative observations about
the pieces of Mg metal at your station
2. Dip them in the bath of CuSO4
3. Record detailed observations in your
notebook
4. Use the “Activity Series” on the right
– Which metal is more reactive,
Copper or Magnesium?
5. What does this remind you of from the
Durability Lab?
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12/17 Electroplating
1. Connect your Nickel to the black wire. Turn on your power
supply. Quickly dip it in and out of the the blue CuSO4
solution. Wipe /scrub firmly with a paper towel. Repeat.
2. On paper, RECORD your observations.
3. WHAT do you think is happening? WHY?
4. WRITE at least 2 questions that you would like to answer
today about what happened in this demo.
5. This technique is called electroplating (coating one metal
with another using electricity). WHY might an artist (or
chemist) use this technique?
Oxidation and Reduction
lose
oxidation
When atoms _________
gain e it is called ___________________.
reduction
When atoms _________ e- it is called ___________________ .
Therefore,
-
LeO
the _____
lion goes
LeO
GeR
GeR
Redox Reactions
Oxidation and reduction always occur together. Therefore,
Redox
these types of reactions are abbreviated ________________
reactions. These reactions are often broken up into
____________________.
half - reactions Some redox reactions occur
____________________,
spontaneously while others require ___________
energy .
Half-reaction
e- Lost or
Gained?
Oxidation OR
Reduction
Electroplating
When metals are __________________
oxidized (lose e-), they can
__________________
dissolve into solution. The reverse is also
possible; when a dissolved metal cation is ________________
reduced
(gains e-) they become uncharged ______________
solid metal
electricity to coat the surface of one
again. Using _________________
metal with another is called ______________________
electroplating .
More Easily Oxidized
Activity Series
Electroplating
eCu2+
Cu0
Cu0
Cu0
SO42-
Cu2+
e-
Cu2+
Cu2+
SO42-
Cu2+
SO42-
Cu2+
Cu2+
SO42-
Cu2+
Cu2+ Cu2+
2-
SO4
Cu2+
cations being
reduced (gaining e-)
and plating as new
solid copper metal
onto the nickel coin
Cu0(s)
SO42-
Cu0 metal being
oxidized (losing e-)
and dissolving into
solution
ePOWER
SUPPLY
Electroplating
Left Side Front Flap
Right Side Front Flap
REDUCTION
OXIDATION
GeR
LeO
Gaining e-
Losing e-
Copper cations in the
solution are becoming
solid and electroplating
onto the surface of the
Nickel as solid Copper
Solid Copper is
dissolving into
Copper cations
Electroplating
Left Side Inside Flap
Right Side Inside Flap
e- travel from the
negative terminal and
build up on the surface
of the Nickel and are
absorbed by Cu cations
which become solid
e- are leaving the piece of
Copper because they are
drawn to the positive
terminal of the power
supply.
GeR
Gaining e- Oxidation
Cu2+(aq) + 2e-  Cu0(s)
LeO
Losing e- Oxidation
Cu0(s)  Cu2+(aq) + 2e-