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Gravimetric Analysis

Hi everyone,

Basically, I need to conduct an experiment to work out the concentration of copper ions in a solution of copper sulphate solution (CuSO4.5H2O). One of the methods I'm using has to be gravimetric analysis, but it's not on the syllabus (so no textbook help), and I can't find any useful links online of how to carry out a procedure.

I need get a copper precipitate by displacing the copper ions with zinc ones (from zinc powder).

Can anyone explain it to me? I have so many questions! How do I know how much zinc to add? It just seems like I should be adding zinc until I just 'know' it's enough...

Any help...muchos appreciated!
Reply 1
Original post by TheDustyKid
Hi everyone,

Basically, I need to conduct an experiment to work out the concentration of copper ions in a solution of copper sulphate solution (CuSO4.5H2O). One of the methods I'm using has to be gravimetric analysis, but it's not on the syllabus (so no textbook help), and I can't find any useful links online of how to carry out a procedure.

I need get a copper precipitate by displacing the copper ions with zinc ones (from zinc powder).

Can anyone explain it to me? I have so many questions! How do I know how much zinc to add? It just seems like I should be adding zinc until I just 'know' it's enough...

Any help...muchos appreciated!


IIRC, trace amounts of copper in solution can be determined by titrating against EDTA with murexide indicator. The colour change should be from yellow to violet. To find a procedure online, look up determination of nickel using EDTA, as nickel and copper can be determined using the same method/conditions.
Original post by TheDustyKid
Hi everyone,

Basically, I need to conduct an experiment to work out the concentration of copper ions in a solution of copper sulphate solution (CuSO4.5H2O). One of the methods I'm using has to be gravimetric analysis, but it's not on the syllabus (so no textbook help), and I can't find any useful links online of how to carry out a procedure.

I need get a copper precipitate by displacing the copper ions with zinc ones (from zinc powder).

Can anyone explain it to me? I have so many questions! How do I know how much zinc to add? It just seems like I should be adding zinc until I just 'know' it's enough...

Any help...muchos appreciated!


How about adding excess zinc...

.. then dissolving the excess in dilute sulphuric acid, leaving the copper behind.
Reply 3
Original post by charco
How about adding excess zinc...

.. then dissolving the excess in dilute sulphuric acid, leaving the copper behind.


I like this idea it sounds promising....any further details? Amound of sulphuric acid? How dilute?
Original post by TheDustyKid
I like this idea it sounds promising....any further details? Amound of sulphuric acid? How dilute?


The details would be for you to sort out.

In principle 2M sulphuric acid reacts with zinc, but not with copper. You just need enough acid to ensure that all of your zinc has gone.

Then filter and wash with lots of water.

Dry and weigh.
Reply 5
Original post by charco
The details would be for you to sort out.

In principle 2M sulphuric acid reacts with zinc, but not with copper. You just need enough acid to ensure that all of your zinc has gone.

Then filter and wash with lots of water.

Dry and weigh.


Merciiii my man!
Would propanone also be needed to use in gravimetric analysis?
How would you make concentrated sulfuric acid?

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