then how bout butane? one or two isomers?

how to name the second one?

This post has been edited by vick5821: Feb 13 2009, 06:06 PM


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Its anyway up to you. But beware to face challenges lo.

alkane nomenclature question:

2-methylbutane

This post has been edited by IamjustME: Feb 13 2009, 09:45 PM

I heard there's changes in PA paper, but so far my PA teacher hasn't inform us the latest updates. Is that true?

Isomers are the compound having similar chemical formula but differ in arrangement of structure.
Both I and II are 5-Carbon molecules.

I: since the longest chain is 5, so it's named pentane, where "pent" = 5 and "ane" = saturated hydrocarbon.
II: the longest chain is 4, with one CH₃ (methyl) branch at carbon position number 2. Hence, 2-methyl-butane.

wa....
at first i thought EE can earn alot
after that the financial crisis came, Electronic sector suffer the most
later i heard EE too many maths(i prefer course that more to physic and less to maths)
besides that my cousin told me EE cannot earn money
in addition LYN member post so many comment about too many ppl still taking EE
finally i made up my mind: go foundation 1st then later took IT/CS
do i made the right choice?

hey all...somebody who hav paper 1 answers for spm 2008 pls giv,i just hv ekonomi asas u wan it? i giv u ...then u giv me the others like math,acc,sn,sj...please?hmm... this is ekonomi asas answers for paper 1.. 1.C 2.D 3.D 4.D 5.D 6.B 7.B 8.B 9.B 10.C 11.C 12.B 13.B 14.A 15.C 16.D 17.C 18.D 19.C 20.B 21.A 22.C 23.D 24.A 25.C 26.A 27.D 28.A 29.C 30.C 31.A 32.B 33.A 34.D 35.A 36.A 37.B 38.C 39.C 40.A...ok,pls share with us too icon_question.gif

Then is methane, ethane and propane have any isomer? butane has 2 isomer( included the straight carbon chain)?

not quit sure but should be 2-methylbutane

Yes, the second one should be 2-methylbutane.

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Added on February 14, 2009, 2:08 pmMethane , ethane and propane have no isomer.


This post has been edited by khaishin: Feb 14 2009, 02:08 PM

Then butane 1 or 2 isomers?

Wat lo now only ask..
I threw my SPM question paper away d .

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Added on February 14, 2009, 5:42 pm

This post has been edited by macamtakada: Feb 14 2009, 05:42 PM

normally isomers can say like got how many molecules can be compared then got how many isomers?

09 SPM candidate here, in literature stream. Scared as hell.

Have been slacking in F4, is it possible to master ekons and sejarah both years within 1 year? Also,thinking of taking Tassawur Islam,good idea?

My friend told me that if you registered for extra subjects and don't come for the exam, it won't be listed in your cert? As in they wont write it as Tak Hadir or fail,just that it wont be in your cert?

For sejarah it is abit hard, but it is only February now, if you study for it from now on,
for sure you can score well !
Hm, for economics, it is easy to catch up.
I took economics during my Form5 March, start studying the syllabus on June.
I am still able to get A in my trial SPM.
It's easy.

From what I know, the small cert, which looks like a paper, it will show TH for the paper you didn't attend.
But in the real cert, it won't show those subjects you TH.

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Added on February 14, 2009, 9:42 pmYou can't think like this.
Hmm, for alkane group, butane is the 1st to have isomers, it has 2 isomers.
For alkene family, butene is the 1st if not mistaken, it has 3 isomers.

If you can't understand, you may memorise the number of isomers for each hydrocarbon.
Reference books as well as text book have them, they are stated clearly in reference books.

You may draw the molecular formulae of those hydrocarbons to get a clearer image in mind.
You would find out why do they have certain amount of isomers.

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Added on February 14, 2009, 9:51 pmDiscussed the answers long long ago and ..those papers have been sold to recycling centre.
Lol..
For sejarah >> http://cikgusejarah.blogspot.com, he posted the answer before, you may find it out there.

This post has been edited by khaishin: Feb 14 2009, 09:56 PM

just memorise ar?

memorise if you can't understand.
My advice for you is draw them in your note book.

those 2 in that picture are 5-carbon molecule. 5-carbon hydrocarbon has 3 isomers. Here are the names, try to draw the structure out to understand it. (1)pentane, (2)2-methyl-butane, (3)2,2-dimethyl-propane. Note: 3-methyl-butane is considered as (2) because we always name the branch at the lowest position

methane, ethane and propane dont have isomers although they have one structural formula whereas butane has 2 isomers including the straight carbon chain structural formula? jiaxun.correct?

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Added on February 15, 2009, 12:56 pmAn add math question
Given a GP x - 1, 10, 3x +2 , p,......express p in terms of x.

how? i can get two answer leh.weird

This post has been edited by vick5821: Feb 15 2009, 12:56 PM

hey all...somebody who hav paper 1 answers for spm 2008 pls giv,i just hv ekonomi asas u wan it? i giv u ...then u giv me the others like math,acc,sn,sj...please?hmm... this is ekonomi asas answers for paper 1.. 1.C 2.D 3.D 4.D 5.D 6.B 7.B 8.B 9.B 10.C 11.C 12.B 13.B 14.A 15.C 16.D 17.C 18.D 19.C 20.B 21.A 22.C 23.D 24.A 25.C 26.A 27.D 28.A 29.C 30.C 31.A 32.B 33.A 34.D 35.A 36.A 37.B 38.C 39.C 40.A...ok,pls share with us too icon_question.gif