[havaliza]

Here is a problem from a chemistry contest of two years ago. I've translated it from Persian but it might have some problems because of my lack of good English.

Problem:
Professor Snape taught Harry Potter the way of making powder A. A little bit of smelling gasses that reek after heating powder A make you laugh. And if you smell too much of it you might rest for a while! Prof. Snape told Harry that in order to make this magic powder he should mix some gastric-juice with crystals of urea and then boil the mixture of these two until there are no bubbles. Then, he said that Harry should add some hell rocks to the obtained solution. After that he should take the sediment B out. The last part of the experiment should be done under moon's light. Then he should let the remaining liquid to evaporate. The white sediment that remains is powder A.
1) What's the chemical formula of urea?
2) Harry found out that this powder has 35% nitrogen, 60% oxygen and hydrogen. Specify the chemical formula of A. Which substances are in it's steam while it's being heated.
3) Can harry use his tin container?
4) Why the last part of chemical reaction has to be done under moonlight.

[havaliza]

I'd wonder if anyone could help me to solve this problem.
thnx

[rosegarden]

I really doubt that whether it is true. I think it does not exist

[csrscience.com]

"A little bit of smelling gasses that reek after heating powder A make you laugh."

This makes me think it is ammonium nitrate, because ammonium nitrate decomposes into N2O, which is laughing gas, and H2O.

HCl and urea might produce ammonium chloride... Adding hell rock - might be some form of a nitrate salt that forms an insoluble chloride - such as lead nitrate or silver nitrate...

Silver chloride is insoluble and reacts with light - so if it is done under moonlight it will not react to much.. 


If silver is more reactive then tin, harry can use his tin container.



Sorry that was super jumbled, but that should put you on a the right track... I think.

[havaliza]

Thank you IndieSci.
I think i should correct this sentence:
"Then, he said that Harry should add some hell rocks to the obtained solution."
should be changed to:
"Then, he said that Harry should add some hell rocks solution to the obtained solution."

[nj_bartel]

Hell rocks definitely makes me thing elemental sulfur.

[Borek]

Hell rocks definitely makes me thing elemental sulfur.

Me too.

[csrscience.com]

Yes but sulfur isn't soluble and it wouldn't react so I don't think that is the case.