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Chemistry MCQ thread...

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@Octahedral
Dude, it seems you're really into Nov 2010's paper, and I did that too today :D. It's D because as far as I think only in 1 will there be Sn1 reaction as that compound is a tertiary alkyl halide.
 
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Zishi said:
hassam said:
thats an R rated questiom

It was really tough question - I got the answer after taking a lot of time. Is the answer 2^7?
Would you mind sharing? But I think such questions isn't our part of the syllabus now which require mathematical formulae of isomers or what.. What do you ppl say?
 
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RafaySid said:
Zishi said:
hassam said:
thats an R rated questiom

It was really tough question - I got the answer after taking a lot of time. Is the answer 2^7?
Would you mind sharing? But I think such questions isn't our part of the syllabus now which require mathematical formulae of isomers or what.. What do you ppl say?

Well, I don't want to mess up the minds of other people at XPF by posting incorrect explanation(just in case if my answer is wrong). And yeah, there's a very low chance of this question coming in a real paper.
 
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well its 2^7...zishi...but i dint understnd a single bit abt this question ........cn u explain
 
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well need help on this question......how i ll figure out valency of Cl in CrO2Cl2....???
 

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hassam said:
well its 2^7...zishi...but i dint understnd a single bit abt this question ........cn u explain

YAY! I got the correct answer for this much tough question... :Yahoo!:

Explanation, I guess is quite difficult, cuz I used like 3 pages of my notebook to get my answer. But here you go:

What can I say is that as there are 6 chiral centres, so there must be 2^6 isomers (times) 2 for cis-trans isomers with H atom(on carbon atoms bonded to a carbon atom with a hydroxyl group) on it.

So 2 x 2^6 = 2^7
 
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hassam said:
well need help on this question......how i ll figure out valency of Cl in CrO2Cl2....???

Cr + 2(-2) + 2(-1) = 0

Cr = +6
D, is the answer.
 
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then where's that rule that said most electronegative element was given the -ve oxidation no.
 
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hassam said:
then where's that rule that said most electronegative element was given the -ve oxidation no.

There are two more electronegative species in it now. So there will be two negative charges and and +ve charge.
 
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hassam said:
SO2Cl2...how to work valency of sulfur in this compound

Sulfur's oxidation is +6 in it - used same way as that of chromium's. I confirmed my answer by drawing covalent bonds, sulfur has formed 6 covalent bonds in this compound.
 
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Ok guys... thats it for me today¬
I'm going to sleep
A VERY BIG THANK YOU FOR EVERYONE!!! I've learned a lot from this thread!
Good luck and Godspeed for everyone taking the test tomorrow¬
Have fun doing it!!!
 
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