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Author Topic: Broken Crystal Form  (Read 2181 times)

Offline wengtech

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Broken Crystal Form
« on: 21/08/2010 15:55:37 »
Dear Friend,
I am having a problem when doing my experiment with potassium alum sulfate which is KAl(SO4)212(H2O)
This is my experience :
- I don't dissolve the alum into water but directly steam it until all melted.
- I let the melted alum cooled it self and become re-solid again.
- After sometimes when hot alum reach the room temperature:
      - at the top surface of solidified alum, some white residue like "snow" begin to form.
      - after several hours the alum will be surrounded with that 'snow'
      - after 2-3 days the solid alum destroyed and completely become powders
- Why is this happen?

some friends says: maybe the alum not pure, so have to add h2so4.

If really have to add h2so4:
- is it "98% h2so4 (concentrated)" or "h2so4 into water solution (what is the best percentage)" ?
- how many % of h2so4 do i have to add into the melted alum?
- is it before or after melting the alum should i add the h2so4?
- is the crystal formed can cause irritation to the skin? (because of we add h2so4 into the solution before)

this still confusing me, so please someone answer my questions.

Thank you a lot.


 

Offline tommya300

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Broken Crystal Form
« Reply #1 on: 22/08/2010 09:32:23 »
Dear Friend,
I am having a problem when doing my experiment with potassium alum sulfate which is KAl(SO4)212(H2O)
This is my experience :
- I don't dissolve the alum into water but directly steam it until all melted.
- I let the melted alum cooled it self and become re-solid again.
- After sometimes when hot alum reach the room temperature:
      - at the top surface of solidified alum, some white residue like "snow" begin to form.
      - after several hours the alum will be surrounded with that 'snow'
      - after 2-3 days the solid alum destroyed and completely become powders
- Why is this happen?

some friends says: maybe the alum not pure, so have to add h2so4.

If really have to add h2so4:
- is it "98% h2so4 (concentrated)" or "h2so4 into water solution (what is the best percentage)" ?
- how many % of h2so4 do i have to add into the melted alum?
- is it before or after melting the alum should i add the h2so4?
- is the crystal formed can cause irritation to the skin? (because of we add h2so4 into the solution before)

this still confusing me, so please someone answer my questions.

Thank you a lot.


"Potassium alum, and alums alike, crystallize in regular octahedral.  It is soluble in water, and when heated it liquefies; and if the heating is continued, an unstructured powder will remain. Potassium alum crystal is colorless and glassy (vitreous), and in its purest form is completely translucent with small fractures."

http://potassiumalum.com/

Wouldn't steaming it add water?

http://www.naturalcosmeticnews.com/focus/the-science-behind-natural-crystal-deodorants/

 

Offline Melvin900

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Broken Crystal Form
« Reply #2 on: 27/09/2010 13:08:06 »
Certainly you experience is very appreciative I think you Spent a lots of time with this experience, I hope you will provide us some more information about that.
 

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Broken Crystal Form
« Reply #2 on: 27/09/2010 13:08:06 »

 

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