URGENT Problems in Chem oct/nov 2010 ppr

[alibalouch]

Ther R many problems in this ppr!!!
but worth discus r the serious mistakes made by examiner

PLZZ PLZZ som one SE THE QUESTION A5 of OCT/NOV 2010 chemistry ppr 5070/22

first ov the the question starts as
A5 CARBON AND GRAPHITE ARE TWO FORMS OF CARBON...
the stament is complete miserable itself

and its C(ii) part says that carbon has triple covalent bond..

hows this possible????


plz help

:x at cambridge

 

[izzahzainab]

In graphite each carbon atom is covalently bonded to three carbon atoms to give trigonal geometry. Three out of four valence electrons of each carbon atom are used in bond formation with three other carbon atoms while the fourth electron is free to move in the structure of graphite.
and just think, carbon has 4 valence electrons, 2 remain in pair, while other two form bond with 4 OXYGEN ATOMS!! 2+3(2)=8 COMPLETE CARBON
OXYEGEN is also complete 2+2(3)=8........................this is the structure :C:::0:

 

[Evilpro]

In graphite each carbon atom is covalently bonded to three carbon atoms to give trigonal geometry. Three out of four valence electrons of each carbon atom are used in bond formation with three other carbon atoms while the fourth electron is free to move in the structure of graphite.
and just think, carbon has 4 valence electrons, 2 remain in pair, while other two form bond with 4 OXYGEN ATOMS!! 2+3(2)=8 COMPLETE CARBON
OXYEGEN is also complete 2+2(3)=8........................this is the structure :C:::0:

@ Izzahzainab: Could you please draw its structure on a piece of paper that would be seriously helpful....man I got this question in a test and i was totally leveled !!
Thanx

 

[SalmanPakRocks]

please use paint software and illustrate by a diagram !! it would be very helpful !!

 

[scouserlfc]

Carbon monoxide is not an ordinary form of bonding it is the same as NH4Cl bond is.This type of bond is called dative bond.

Well go in the link below it is one of my favourite sites for chemistry,youll find in the last carbon monooxide structure.And yes it is a triple covalent compound.

http://www.chemguide.co.uk/atoms/bonding/dative.html

Well the person who wrote the fist post has made a big mistake if you look at the question here http://goo.gl/ppZSw Look at c(ii) part.
In the question it is said that carbon monooxide has a triple covalent bond and not only carbon clear that misconception out .

 

[SalmanPakRocks]

thanks @Scouserlfc !!

 

[scouserlfc]

No prob mate, I hope the post starter understands this all.

 

[SalmanPakRocks]

 

[Evilpro]

ohhh...CHEMIXTRY is such a MYSTERY !!!

 

[SalmanPakRocks]

ohhh...CHEMIXTRY is such a MYSTERY !!!

Agree with you !! I hate chemistry! Wonder why i took it !!

 

[scouserlfc]

I love chemistry and all other science subjects.Well sorry to say that LOL . :lol:

 

[Bloodlines]

@scouserlfc . Me too

 

[Bloodlines]

Is there anyon who could help in preparation of Urdu A.

 

[SalmanPakRocks]

Bloodlines I have taken Urdu B !! Urdu A is very difficult why are you giving A ??

 

[scouserlfc]

Yeah it is extremely difficult but we could help you if you tell whats in your syllabus,

 

[SalmanPakRocks]

Yeah it is extremely difficult but we could help you if you tell whats in your syllabus,

http://www.xtremepapers.net/CIE/Cambrid ... y11_sy.pdf
here is the syllabus !!