Chemical Forums
Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: fm on June 14, 2009, 04:28:16 PM
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which of these are soluble in hexane? Thanks for the help and it would be much appreciated if someone could tell me why too :)
NaCl
CaSO4
KAL(SO4)2
KNO3
NH4NO3
Cu(NO3)2
C2H5OH
C12H22O11
Kerosene
Toluene
Glycerin
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Please read forum rules (http://www.chemicalforums.com/index.php?topic=33740.0). It would be much appreciated.
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well so far I have it like this:
NaCl insoluble
CaSO4 insoluble
KAL(SO4)2 insoluble
KNO3 soluble
NH4NO3 soluble
Cu(NO3)2 insoluble
C2H5OH insoluble
C12H22O11 insoluble
Kerosene soluble
Toluene soluble
Glycerin insoluble
It was a lab experiment so I don’t really know the theoretical explanation as to why is that. I came up with those answers just by observation, so I want to make sure that my answers are correct and understand the explanation behind it. The ones that I'm really not sure about are NH4NO3 and KNO3.
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Polar, ionic...
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thanks you are a great help.
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Hello,
I cannot explain this topic fully, but I can give you some ideas as to where to look. This is a really good experiment.
If you take a look inyour basic undergraduate organic textbook, you can find the explanation for this solubility.
The text I am using is Streitweiser, Heathcock and Kosower Introduction to Organic Chemistry, 4th edition.
In this text, in the basic section of nuclophilic reactions, they talk about solvent properties. on Page 184, there is a simple explanation of what happens when you dissolve a salt in a solvent. The Dielectric Constant is a measure of the reduction of the Electric Field in the medium, and materials that are polar, will align with charges in solution, and with thermal motion, will move closer to the ions. The dielectric constant of the medium will tell you the polarity of the solvent, and will indicate how well it will solubilize salts, and ions in solution.
Hexanes should not solubilize hardly any salts at all. The fact that it does means that the bonds are fairly weak in the salt, it would have to be stabilized by thermal velocity to prevent crystallization. Take a look at the bond strengths of the salts, and remember to include resonance stabilization, and compare the solubilities of the salts in various dielectric constant solutions.
Hopefully this should give a good direction to take a look at.