Need some organic chem worksheets/ questions
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Originally posted by dkcx:
If u interested, try naming these.
a) C - C - C - C - C
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C - C - C
b) C - C - C -C
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C - C
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C - C
c) C - C - C -C - C
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C C - C
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Cok boss. so now i just name these 3 right... here goes...
a) propylpentane
b)2-diethylbutane
c) cant see which carbon the most right chain is connected to...
but... 2-ethyl-4-propylpentane
i think b and c wrong.
i believe got C . longest carbon chain is 6 . if 2nd branch connected to 4th C . then is 7 is connected to 5th C .
while for B. got 2 longest carbon chain of 4.
but then where all the hydrogen gone to ._.
awaiting dkcx reply. thanks.
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Originally posted by yiha093:
ok boss. so now i just name these 3 right... here goes...
a) propylpentane
b)2-diethylbutane
c) cant see which carbon the most right chain is connected to...
but... 2-ethyl-4-propylpentane
i think b and c wrong.
i believe got C . longest carbon chain is 6 . if 2nd branch connected to 4th C . then is 7 is connected to 5th C .
while for B. got 2 longest carbon chain of 4.
but then where all the hydrogen gone to ._.
awaiting dkcx reply. thanks.
a) A propylpentane can never exist so please check again and remember you need number the side chain.
b) Your longest chain is wrong. If diagram is misleading, the connecting point is with the 2nd C of the top 4. If u can find 2 longest chain that is 4 and they are named differently, it normally means that is not the longest chain since such a molecule would have problems being named.
c) Connection is 4th C in the top 5. As with a), propylpentane is none existant. Another thing to note, your answer totals to 10C but my diagram only has 9C. When doing naming of organic molecules, always crosscheck and make sure your number of carbons are the same.
Good attempt though, try again and get it correct.
Organic chemist do not bother to draw in the H as we always deal with large molecules and adding in all the H makes the structure too complicated. Its always understood that H are automatically added to all the Cs. In fact we do not even write out the Cs but just draw lines.
Eg. W is a pentane molecule to us and how we will draw it rather than
C - C - C - C -CRegarding the diagrams, its hard to align them properly cos it looks align when i write it but when i post, alignment is wrong. This might be due to each individual display settings etc i'm not sure so i can't really help it.
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Originally posted by dkcx:
a) A propylpentane can never exist so please check again and remember you need number the side chain.
b) Your longest chain is wrong. If diagram is misleading, the connecting point is with the 2nd C of the top 4. If u can find 2 longest chain that is 4 and they are named differently, it normally means that is not the longest chain since such a molecule would have problems being named.
c) Connection is 4th C in the top 5. As with a), propylpentane is none existant. Another thing to note, your answer totals to 10C but my diagram only has 9C. When doing naming of organic molecules, always crosscheck and make sure your number of carbons are the same.
Good attempt though, try again and get it correct.
Organic chemist do not bother to draw in the H as we always deal with large molecules and adding in all the H makes the structure too complicated. Its always understood that H are automatically added to all the Cs. In fact we do not even write out the Cs but just draw lines.
Eg. W is a pentane molecule to us and how we will draw it rather than
C - C - C - C -CRegarding the diagrams, its hard to align them properly cos it looks align when i write it but when i post, alignment is wrong. This might be due to each individual display settings etc i'm not sure so i can't really help it.
so i assume one carbon bonded to 3 Hydrogen ba ?
a ) ethylhexane ?
b) longest chain is 6. 2-ethyl-3-ethylhexane ?
c)2-methyl-4-methyl-5methylhexane
please mark ty boss
u the guy uni course sth to do with chemistry 1 right. LOL
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Originally posted by yiha093:
so i assume one carbon bonded to 3 Hydrogen ba ?
a ) ethylhexane ?
b) longest chain is 6. 2-ethyl-3-ethylhexane ?
c)2-methyl-4-methyl-5methylhexane
please mark ty boss
u the guy uni course sth to do with chemistry 1 right. LOL
a) Wheres ur numbers? Ethylhexane though it won't be wrong since an ethyl group can only appear in 1 place but still its a good practice to always put in your position numbers.
b) Your answer is a 10C molecule while mine is a 8C molecule. There is also no ethylethyl. Its always 2,3-diethyl for your case of writing.
c) no methyl methyl methyl as well. Its 2,4,5-trimethylhexane which will be correct :)
Yeah i'm doing a chemistry degree in NTU.
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Originally posted by dkcx:
a) Wheres ur numbers? Ethylhexane though it won't be wrong since an ethyl group can only appear in 1 place but still its a good practice to always put in your position numbers.
b) Your answer is a 10C molecule while mine is a 8C molecule. There is also no ethylethyl. Its always 2,3-diethyl for your case of writing.
c) no methyl methyl methyl as well. Its 2,4,5-trimethylhexane which will be correct :)
Yeah i'm doing a chemistry degree in NTU.
wa mai siao siao. i got 2 correct sia. xD
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paiseh. made a mistake. is methyl not ethly -.-'' for B
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I will say 1.5 rather than 2 cos i won't give u full marks for a) without the number.
yes, b) is 2,3-dimethylhexane
Don't be careless though but it seems you roughly have an idea what u are doing now.
Need more practice or want more challenges involving naming for alkenes, alcohols and acids? :p
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Originally posted by dkcx:
I will say 1.5 rather than 2 cos i won't give u full marks for a) without the number.
yes, b) is 2,3-dimethylhexane
Don't be careless though but it seems you roughly have an idea what u are doing now.
Need more practice or want more challenges involving naming for alkenes, alcohols and acids? :p
ok lor. i need practise also. but i shall not hijack anpanman thread. LOL.
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anpanman, the answers have been given but try to understand why the answers are what they are and do ask if you are in doubt. Good luck :)
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idk...
i didn't even learn this in school yet~!!!!!!!!!!!!!!!!!!1
our school is like so slow la~
xian~...
but i'll giv it a shot lo.... idk liao~
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Originally posted by tr@nsp0rt_F3V3R:
idk...
i didn't even learn this in school yet~!!!!!!!!!!!!!!!!!!1
our school is like so slow la~
xian~...
but i'll giv it a shot lo.... idk liao~
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na~ off MSN le... cuz can only conc. on one place nia~...
so since i'm in sgf, focus on sgf lor~
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haha. i forgot my answer liao.
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Originally posted by tr@nsp0rt_F3V3R:
na~ off MSN le... cuz can only conc. on one place nia~...
so since i'm in sgf, focus on sgf lor~
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Originally posted by yiha093:
haha. i forgot my answer liao.
huh?
ps ar... too wordy le~
idk how to read leh~
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Originally posted by yiha093:
haha. i forgot my answer liao.
Questions are meant to be worked out and not answers memoried. If u redo them and cannot be correct then u better spent more time studying and understand what you are doing.
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Originally posted by tr@nsp0rt_F3V3R:
huh?
ps ar... too wordy le~
idk how to read leh~
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Originally posted by dkcx:
Questions are meant to be worked out and not answers memoried. If u redo them and cannot be correct then u better spent more time studying and understand what you are doing.
ya lor~
must understand what i am doing also...
why my school so slow ar? made me lose face here?!
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So slow until i oso sort of forget the meaning of sorry le~
maybe gonna post one thread and ask P1 kids to explain what sorry means....
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Originally posted by tr@nsp0rt_F3V3R:
So slow until i oso sort of forget the meaning of sorry le~
maybe gonna post one thread and ask P1 kids to explain what sorry means....
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Originally posted by dkcx:
Words loss meaning fast when they are overuse.
Good luck studying then, don't find me for anything else
Oh... eu know the meaning of sorry, kinda share what it means?
cuz i really need to know it
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Originally posted by tr@nsp0rt_F3V3R:
Oh... eu know the meaning of sorry, kinda share what it means?
cuz i really need to know it