Copper Sulfate Reaction
Date: Around 1999
I am doing a science project. I added water to copper
sulfate and then put a piece of aluminium foil into it. The solution put
hole in the foil. I would like to find out why? Any additional info
First a little bit of theory...The metals (as Aluminum and Copper) react
differently, beeing some "more active"
That chemical activity reflects the greater or lesser
facility to give up their electrons. If one metal is
brought into contact with the ions of another metal,
one of two things can happen. Either the metal can
transfer electrons to the ions (and a reaction occurs)
or the ions do not accept the electrons (no reaction
The metals can be arranged in an activity series with
the most reactive at the top and the least reactive at
Now for your question: at that activity series Aluminum
is above Copper. That is, in your solution of Copper
Sulphate you have Copper ions (and Sulphate ions).
When you add Aluminum foil to the solution, the metal
Aluminum will transfer electrons to the Copper ions,
and Aluminum ions will be formed instead.
2 Al + 3Cu (+2) = 2 Al(+3) + 3Cu
That is why you see a hole in the foil indicating
that the Al (+3) ions went into solution. At the same
time metalic Copper will be formed and gradually will
make a deposit.
That is it! Thanks for asking NEWTON!
(Dr. Mabel Rodrigues)
Click here to return to the Chemistry Archives
Update: June 2012