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Author Topic: ALL CIE CHEMISTRY DOUBTS HERE !!  (Read 119131 times)

elemis

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #450 on: April 19, 2011, 02:32:35 pm »
Quote from: thecandydoll on April 19, 2011, 02:17:33 pm
A few of the organic questions in A2 Paper 4 are in the form of skeletal forumla.How do you do it?

What do you mean by 'how do you do it ?'.

You have to be more specific if you want any constructive help or people will be simply put off by the ambiguous nature of your questions.
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Offline red_911

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #451 on: April 19, 2011, 06:03:28 pm »
water has which types of intermolecular forces ?? n which has higher boiling point HF or h2O ? explain with reason plzz ???
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Amelia

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #452 on: April 19, 2011, 06:30:01 pm »
Quote from: red_911 on April 19, 2011, 06:03:28 pm
water has which types of intermolecular forces ??
Hydrogen Bonds.

Quote
n which has higher boiling point HF or h2O ? explain with reason plzz ???

Water has two hydrogens while HF has only one. So, obviously the water will make multiple bonds (three) and when together then form a greater intermolecular force than that of HF, since HF can form hydrogen bonds with only two other atoms. 
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Offline thecandydoll

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #453 on: April 20, 2011, 09:16:37 am »
How do you UNDERSTAND THE SKELETAL formula...

What do those lines depict?

 i haveseen you in tsr
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Offline Master_Key

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #454 on: April 20, 2011, 01:18:46 pm »
Quote from: thecandydoll on April 20, 2011, 09:16:37 am
How do you UNDERSTAND THE SKELETAL formula...

What do those lines depict?

 i haveseen you in tsr

The Points on line depict Carbon atoms. If it is just a change of line means Carbon-Hydrogen atoms. If Chlorine or smth else is there then it must be specified.
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Offline EMO123

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #455 on: April 24, 2011, 09:08:51 am »
What word describes the petrochemical industry process of converting straight chain alkanes into cycloalkanes, cycloalkenes and aromatics?
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Offline HUSH1994

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #456 on: April 24, 2011, 12:56:04 pm »
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Offline red_911

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #457 on: April 25, 2011, 09:21:30 pm »
which one of these have higher boiling point: alkanes, alkenes, carboxylic acids or halogenoalkanes ... explain all a little please  ???
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Offline EMO123

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #458 on: April 26, 2011, 03:47:23 am »
i think you should read it from your book it is fully explained
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Offline SkyPilotage

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #459 on: April 26, 2011, 08:01:39 pm »
Quote from: red_911 on April 25, 2011, 09:21:30 pm
which one of these have higher boiling point: alkanes, alkenes, carboxylic acids or halogenoalkanes ... explain all a little please  ???

It depends on the intermolecular forces between the molecules, which are Van-der-waals, permanent dipole-dipole and hydrogen bonds( type of Perm. Dipole-Dipole).
Strength of Hydrogen bonds>permanent dipoles>van-der-waals.
As electrons increase, van-der-waals increase since they are actually induced dipoles from the movement of e's.
Hydrogen bonds form between N,O,F lone pair and H.
So if you are talking abt corresponding alkanes<alkenes<alchohols<carboxylic acids. Ofcourse as Carbon atoms increase m.p and b.p increases!
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Offline SkyPilotage

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #460 on: April 26, 2011, 08:06:54 pm »
Quote from: Amelia on April 19, 2011, 06:30:01 pm
Hydrogen Bonds.

Water has two hydrogens while HF has only one. So, obviously the water will make multiple bonds (three) and when together then form a greater intermolecular force than that of HF, since HF can form hydrogen bonds with only two other atoms. 

Doesnt water have all three? van der wall + perm dipoles + hydrogen bonds? I think all molecules have Van-der-waals...except ideal gases (anthr story)
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Offline HUSH1994

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #461 on: April 27, 2011, 07:41:07 am »
ON 2003 P1 Q20,how do u solve this type of question,is there another way other than drawing the structures?
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elemis

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #462 on: April 27, 2011, 08:41:53 am »
Quote from: ~~!$!HUSH!$!~~ on April 27, 2011, 07:41:07 am
ON 2003 P1 Q20,how do u solve this type of question,is there another way other than drawing the structures?

Nope, there's no other way.
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Offline $H00t!N& $t@r

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #463 on: April 28, 2011, 07:51:39 pm »
Hi
Can someone please explain q2 d (ii) 2010 O/N var 23  in detail
Thanks
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A=X+Y+Z, X is work. Y is play. Z is keep your mouth shut"- Albert Einstein

Offline Vin

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Re: ALL CIE CHEMISTRY DOUBTS HERE !!
« Reply #464 on: April 28, 2011, 08:09:50 pm »
Can you please post the paper?
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