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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: msandra on July 17, 2004, 05:43:50 PM

Title: how to tell from the reaction that there was unreacted copper(II) chloride
Post by: msandra on July 17, 2004, 05:43:50 PM
i was asked how to tell from the reaction that there was unreacted copper(II) chloride present.

During the experiment, the blue colored solution gradually becaomes clear. Didn't it mean all the Cu is used up? How can i tell there is still unreacted CuCl2.

Can anyone give me some ideas or brainstorm?

should I carry out any test to test the presence of CuCl2?
Title: Re:how to tell from the reaction that there was unreacted copper(II) chloride
Post by: Donaldson Tan on July 18, 2004, 01:29:20 PM
u could try adding reagents to precipiate any Cu2+ and Cl- out
Title: Re:how to tell from the reaction that there was unreacted copper(II) chloride
Post by: msandra on July 18, 2004, 08:50:16 PM
During the experiment, Cu metal is deposited on the iron nail and in the CuCl2 solution.

The solution is then filtered by filter paper to obtain copper metal.  Distillated water, 1M HCl and Distillated water is used to wash the copper on the filter paper alternatively.

why we need to wash it with HCl and water? will it make Copper metal dissolved in the solution again?
Title: Re:how to tell from the reaction that there was unreacted copper(II) chloride
Post by: Mitch on July 19, 2004, 07:08:54 PM
The HCl is probably just used to help filter any salts that become soluble in acid.
Title: Re:how to tell from the reaction that there was unreacted copper(II) chloride
Post by: msandra on July 19, 2004, 10:50:51 PM
i don't understand , can you give me more detail?

what is the salt that soluable in acid?

Thanks
Title: Re:how to tell from the reaction that there was unreacted copper(II) chloride
Post by: Mitch on July 20, 2004, 01:10:06 AM
cupper salts