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Topic: Problem of the week - 11/06/2012  (Read 7832 times)

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Online Borek

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Problem of the week - 11/06/2012
« on: June 11, 2012, 09:03:45 AM »
Low boiling hydrocarbon A reacts with hydrogen bromide producing compound B containing 53.6% bromine. Same compound A reacts with bromine producing compound C containing 70.1% bromine. Oxidation of compound A with permanganate in acidic solution yields compound D containing 48.4% oxygen (and no other elements but CHO). Compounds A, B and D don't contain asymmetric carbons. Name all compounds (if reaction can yield more than one product, list them all).

Edit: mistake corrected.
« Last Edit: June 11, 2012, 04:54:40 PM by Borek »
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Offline fledarmus

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Re: Problem of the week - 11/06/2012
« Reply #1 on: June 11, 2012, 10:04:48 AM »
None of these compounds contains an asymmetric carbon.

Does this mean that A, B, C, and D will have neither enantiomers or be meso structures?

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Re: Problem of the week - 11/06/2012
« Reply #2 on: June 11, 2012, 10:33:48 AM »
Yes.

Or at least that's my understanding. It is not very easy, but doable - you can confuse me with stereochemistry  :-\
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Offline AWK

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Re: Problem of the week - 11/06/2012
« Reply #3 on: June 11, 2012, 01:54:28 PM »
 C - racemate
AWK

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Re: Problem of the week - 11/06/2012
« Reply #4 on: June 11, 2012, 04:53:36 PM »
Sigh. A, B and D don't contain assymetric carbons.

Original post corrected.
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Offline DrCMS

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Re: Problem of the week - 11/06/2012
« Reply #5 on: June 11, 2012, 06:28:46 PM »
OK now you've changed C I think it might be:

A = cyclopentene
B = bromocyclopentane
C = trans 1,2-dibromocyclopentane
D = glutaric acid

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Re: Problem of the week - 11/06/2012
« Reply #6 on: June 12, 2012, 12:07:14 PM »
And that's the correct answer.

Looks like the best way to attract people to the Problem of the week is to make a stupid error in the question  :P
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Offline DrCMS

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Re: Problem of the week - 11/06/2012
« Reply #7 on: June 12, 2012, 12:25:31 PM »
Looks like the best way to attract people to the Problem of the week is to make a stupid error in the question  :P

It's only a couple of errors you've made and it does say in your signature that "I am known to be occasionally wrong" so nodody can complain about it.

This one did have me scratching my head thinking "all the rest works and cis-1,2-dibromocyclopentane fits but it's not the product formed with bromine or have I got that wrong"  thankfull it was nothing as serious as me being wrong it was you  ;)

For the methyl radicals and antimony mirrors one I looked at that and thought "don't you need the flow rate?" and nearly posted to that but then I thought maybe there's some fancy maths that means you don't.  

Ah well no real harm done and these questions do make me use my brain more that some of the other questions asked here.

Offline fledarmus

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Re: Problem of the week - 11/06/2012
« Reply #8 on: June 12, 2012, 04:35:15 PM »
Just because we're not commenting on them doesn't mean we're not reading them - and enjoying the test!

An old joke, retold as recently as http://www.madisonrecord.com/arguments/224033-the-day-the-toast-wasnt-burnt

"The story is told of the seven-year-old boy who never spoke. None of the specialists his parents had taken him to see could identify the source of his silence. Then one morning at the breakfast table a voice exclaimed: "This toast is burnt."

Their son had spoken at last! The parents jumped for joy, hugged their offspring and phoned friends and relatives to share the news.

As the excitement ebbed, curiosity grew and the mother inquired: "Son, why have you never spoken before?"

"Gee, mom," the boy replied, "up 'til now, everything's been fine.""


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