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#Post#: 956--------------------------------------------------
Problem of the week- 22/10/12
DIR By: Michel
Date: October 22, 2012, 8:16 am
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Two gases, A and B are combined at 200'C to produce a
crystalline solid, C. On heating, C decomposes into a highly
volatile liquid, D with the evolution of gas B. Eventually, D
polymerizes into a crystalline solid, E 1 containing 67%
nitrogen by mass, the rest being Carbon and Hydrogen, and having
a molar mass of 126g/mol
Name the compounds A-E
now you know gases A & B are not elements ;-)
1 I have left some little detail on the polymerization which I
might reveal later on
#Post#: 959--------------------------------------------------
Re: Problem of the week- 22/10/12
DIR By: Potla
Date: October 22, 2012, 11:57 am
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I dunno if this is right, but I guess A=CO2, B=NH3,
C=NH2-CO-NH2. At 200 C, A and B combine to give Urea(which is a
crystalline solid), and on heating urea we get NH3 and HNCO. 6
molecules of HNCO react to give away CO2 and melamine (E).
CO2+2NH3 = NH2-CO-NH2+H2O
NH2-CO-NH2 = NH3+HNCO
6HNCO = 3CO2+C3N6H6 (E)
And E has 67% N by weight as well. :)
#Post#: 962--------------------------------------------------
Re: Problem of the week- 22/10/12
DIR By: Michel
Date: October 22, 2012, 12:27 pm
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--- Quote from: Potla link ---
>
> I dunno if this is right
>
--- End Quote ---
well, you know it's right ;)
Thumbs up!
The quickest solution yet to a POTW...here's an applause ;)
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