PURIFYING COPPER METALPURIFYING COPPER METAL

• This shows how very pure copper is This shows how very pure copper is produced from crude copper metal.produced from crude copper metal.

• It needs to be very pure for things It needs to be very pure for things like ELECTRICAL WIRES so that like ELECTRICAL WIRES so that

they conduct very well.they conduct very well.

We use electrolysis to move the copper from an impure We use electrolysis to move the copper from an impure lump to a piece of pure copper.lump to a piece of pure copper.

THROUGH THE SOLUTIONTHROUGH THE SOLUTION ! !

CRUDECRUDE

CuCuPURE CuPURE Cu

++

ImpuritiesImpurities

We need a solution of Copper We need a solution of Copper ionsions

Cu Cu 2+2+

We’ll use Copper SulphateWe’ll use Copper Sulphate

Next we need a piece ofNext we need a piece of

IMPURE copperIMPURE copper

We make it the positive electrode

Then we add a thin pure copper electrode

And make it the negative electrode

--

--

--

--

With negative electrons waiting to be collectedWith negative electrons waiting to be collected

--

--

--

--

Positive copper ions in the solution move to the negative electrodePositive copper ions in the solution move to the negative electrode

Cu Cu 2+2+

Cu Cu 2+2+

--

--

--

--

Cu Cu 2+2+

Cu Cu 2+2+

--

--

--

--

They collect 2 electrons each and becomeThey collect 2 electrons each and become

Cu atoms that COAT the electrodeCu atoms that COAT the electrode

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

Cu 2+ + 2e → Cu

CuCu

At the same time Copper atoms give up 2 electrons each At the same time Copper atoms give up 2 electrons each

and enter the solution from the IMPURE copperand enter the solution from the IMPURE copper

Cu Cu 2+ + 2e

CuCu

CuCuCuCu

CuCu

At the same time Copper atoms give up 2 electrons each At the same time Copper atoms give up 2 electrons each

and enter the solution from the IMPURE copperand enter the solution from the IMPURE copper

Cu → Cu 2+ + 2e

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

Cu → Cu 2+ + 2e

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

And they then move across through the solution toAnd they then move across through the solution to

NEGATIVE ELCTRODENEGATIVE ELCTRODE

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

The impurities then fall to the bottom as the copper coats The impurities then fall to the bottom as the copper coats

NEGATIVE ELECTRODENEGATIVE ELECTRODE

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

Eventually all of the copper moves across and theEventually all of the copper moves across and the

POSITIVE electrode disappearsPOSITIVE electrode disappears

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCuCu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCu

Cu Cu 2+2+

Cu Cu 2+2+

CuCu

CuCuCuCu

CuCu

CuCu

CuCuCu Cu 2+2+

CuCu

CuCuCu Cu 2+2+

CuCu

CuCuCuCu

CuCuCuCu

CuCu

CuCu

CuCuCu Cu 2+2+

CuCu

CuCuCu Cu 2+2+

CuCu

CuCuCuCu

CuCuCuCu

CuCu

We eventually get a fat pure copper electrode as all of the copperWe eventually get a fat pure copper electrode as all of the copper

is deposited onto itis deposited onto it

We eventually get a fat pure copper electrode as all of the copperWe eventually get a fat pure copper electrode as all of the copper

is deposited onto itis deposited onto it

PurePure

CuCu

That’s all, folks!!That’s all, folks!!