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xyzphineR
Jan13-05, 09:30 AM
As we know, there are several method for separating mixture(separation) for different cases, they are Filtration, Evaporation, Crystallization, Distillation, Fractional distillation, using Separating funnel to separate two immiscible liquids and Paper chromatography to separate small amount of substances in a mixture. And now I have two questions, I hope somebody can answer me :smile:

1. Except we clip the CaCO3 directly after the filtration, how can separate and get the CaCO3 when the solution was like this : A mud-water with CaCO3 inside.

2.How can we separate this mixture?
Hexane + CuCl2 (and also the water of course)

Apologize for my poor english :biggrin:

chem_tr
Jan13-05, 12:48 PM
Well, your first question may be solved by various ways, I am not sure which will fit your needs. However, you can use ethylenediamine tetraacetic acid (EDTA) to form a calcium complex at pH=12, and filter it to remove from muddy water. Calcium ion can be released by mixing this solution with a metal ion which will give a more stable complex with EDTA, say, copper ions.

Hexane and aqueous copper chloride solution are not miscible with each other, just using a separating funnel will work; I think the aqueous solution has a greater density than hexane, so it will form the bottom layer. Removing it from hexane layer will give you a slightly hexane-involved aqueous solution, the hexane can be removed by boiling the solution for a little time, as its boiling point is lower than that of water.

xyzphineR
Jan14-05, 07:46 AM
Well, your first question may be solved by various ways, I am not sure which will fit your needs. However, you can use ethylenediamine tetraacetic acid (EDTA) to form a calcium complex at pH=12, and filter it to remove from muddy water. Calcium ion can be released by mixing this solution with a metal ion which will give a more stable complex with EDTA, say, copper ions.

thanks for your answer my man :biggrin: but i still have the main problem for the first question, which is "obtain / get the CaCO3 from the muddy water", if i have not make a mistake from your answer, using ethylenediamine tetraacetic acid will release Calcium ion right? but then all i need is CaCO3 :o)

maybe you can tell me another way to get CaCO3 from the muddy water^^

chem_tr
Jan14-05, 03:32 PM
Maybe you can try this one: Wash the muddy water sample with hot dilute HCl solution, the calcium carbonate will be converted into calcium chloride, CaCl2, and by filtering you will remove this solution from muddy water. Then you require that the calcium ions be in the form of carbonate, add sodium carbonate until all calcium has been precipitated, and filtering this one again will give you the desired product.

xyzphineR
Jan15-05, 10:21 AM
thanks thanks =DDDDD