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#Post#: 902--------------------------------------------------
Explain why??
DIR By: LikeCrazy
Date: October 16, 2012, 3:35 pm
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Ok so I was trying out a little kitchen chem ^-^ and I made a
conc solution of potash alum, then I added a little methylated
spirit (95% ethanol) and a white ppt was formed...i think the
ppt is AlOH3 but i'm wondering about the chemical reaction that
occured....any thoughts? :-D
#Post#: 921--------------------------------------------------
Re: Explain why??
DIR By: Cheminized
Date: October 17, 2012, 3:36 pm
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first : what do you mean by potash alum.
second: its known that adding alcohol to aqueous solutions of
electrolytes would lower the solubility of the electrolyte so
most probably the white ppt is your potash alum. ???
#Post#: 1055--------------------------------------------------
Re: Explain why??
DIR By: LikeCrazy
Date: November 6, 2012, 8:49 pm
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Potash alum is alum i think a double salt
#Post#: 1056--------------------------------------------------
Re: Explain why??
DIR By: LikeCrazy
Date: November 6, 2012, 8:53 pm
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Okay i checked my textbook it is K2SO4.Al2(SO4)3.24H2O
it is a soluble salt, then wy will a ppt form when i add the
spirit?
#Post#: 1143--------------------------------------------------
Re: Explain why??
DIR By: Michel
Date: November 17, 2012, 4:57 am
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Probably lowering temperature causing precipitation? Did the
precipitate clear after a while?
#Post#: 1152--------------------------------------------------
Re: Explain why??
DIR By: Shiva
Date: November 18, 2012, 3:02 am
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Added to Michel's questions, have you mixed them in dry
conditions or what? Also, at what temperature it gave the white
precipitate? Most probably, it is sulfovinic acid. Not sure
though. Based on your response, I will try this in my lab for
you :-)
Shiva
#Post#: 1179--------------------------------------------------
Re: Explain why??
DIR By: syed hussain ali
Date: November 19, 2012, 3:58 pm
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Potash alum is an ionic compound and alcohol is an organic
derivative it can not dissolved in and forms ppt.
#Post#: 1183--------------------------------------------------
Re: Explain why??
DIR By: Michel
Date: November 20, 2012, 6:51 am
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--- Quote from: syed hussain ali link ---
>
> Potash alum is an ionic compound and alcohol is an organic
derivative it can not dissolved in and forms ppt.
>
>
--- End Quote ---
That could be what happened...but I'm not sure. You could test
by checking if your precipitate is soluble in water
#Post#: 1189--------------------------------------------------
Re: Explain why??
DIR By: Shiva
Date: November 21, 2012, 7:36 am
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Likecrazy was right. I've prepared Potash alum today and it
gives white precipitate at RT on adding Ethanol. Now, me goanna
test both Potassium and Aluminium sulfate separately.
Shiva
#Post#: 1191--------------------------------------------------
Re: Explain why??
DIR By: Michel
Date: November 21, 2012, 12:00 pm
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--- Quote from: Shiva link ---
>
> Likecrazy was right. I've prepared Potash alum today and it
gives white precipitate at RT on adding Ethanol. Now, me goanna
test both Potassium and Aluminium sulfate separately.
>
> Shiva
>
--- End Quote ---
Surely, K2SO4 will produce no ppt;)
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