.............Completely free online preparation, original content, for the Chemistry SAT exam.It has never been that simple: you want to ace the .............SAT exam? Just practice.
You want to practice? Here you find completely free preparation, weekly updated chemistry quizzes and .............feedback support. All for free of course.
Thursday, 1 March 2007
SAT Question of the Day
How many isomers could hypothetically exist with the molecular formula C3H5Cl?
I will give the right answer tomorrow. I am actually a student in the university (chemistry, of course) but during the high school I participated 3 times in International Olympiads (I have been awarded the gold medal only once, though). Actually when I took the SAT at chemistry i did not prepare at all - but I "aced" it - and I became involved in this blog only when some of the students to whom I have been TA started to ask me questions about chemistry and about SAT.
are u from USA? at what university do u study??? I am from Romania and I have almost 3 years until i have to choose a university but i ont know what to do...to go outside or to stay here. i participate at national olympic at chemistry this year..and i participated ;last year too:)
There are 5 isomers: Just make sure to include cis and trans isomers as two different ones, and to draw also the cyclopropane ring with a chlorine attached and that's it.
I see one, since the carbons have to be in the center H and Cl only need one more electron to be complete. that means everything is single bonded with a carbon in the middle right? no wait carbon has 4 valence arggh, im new to this,,,:( 2 double bonds so no triple or recursion, draw a picture and post it anyone?
So, this are the structures of the isomers: cis CH3-CH=CHCl trans CH3-CH=CHCl CH3-CCl=CH2 CH2Cl-CH=CH2 Chlorocyclopropane - a cyclopropane with a chlorine attached.
woah i kinda did it differently (didnt use cis and trans and the cyclopropane, but just wrote out the structural formula) but got the same answer .. wats the cyclopropane ?
17 comments:
5 ?
I found 4:( Is that corect. blog owner are you a teacher or sth like that???
Nice demonstration at the last Ace Chemistry SAT II
is that corect?*
I will give the right answer tomorrow.
I am actually a student in the university (chemistry, of course) but during the high school I participated 3 times in International Olympiads (I have been awarded the gold medal only once, though). Actually when I took the SAT at chemistry i did not prepare at all - but I "aced" it - and I became involved in this blog only when some of the students to whom I have been TA started to ask me questions about chemistry and about SAT.
are u from USA?
at what university do u study??? I am from Romania and I have almost 3 years until i have to choose a university but i ont know what to do...to go outside or to stay here. i participate at national olympic at chemistry this year..and i participated ;last year too:)
There are 5 isomers:
Just make sure to include cis and trans isomers as two different ones, and to draw also the cyclopropane ring with a chlorine attached and that's it.
I forgot the cyclopropane ring:(
I see one, since the carbons have to be in the center H and Cl only need one more electron to be complete. that means everything is single bonded with a carbon in the middle right? no wait carbon has 4 valence arggh, im new to this,,,:( 2 double bonds so no triple or recursion, draw a picture and post it anyone?
yay it got it rite ! hehe
So, this are the structures of the isomers:
cis CH3-CH=CHCl
trans CH3-CH=CHCl
CH3-CCl=CH2
CH2Cl-CH=CH2
Chlorocyclopropane - a cyclopropane with a chlorine attached.
woah i kinda did it differently (didnt use cis and trans and the cyclopropane, but just wrote out the structural formula) but got the same answer .. wats the cyclopropane ?
cyclopropane is a cycle of 3 atoms of C
like this CH2
/ \
CH2-CH2
its not that stable because of the tension in the cicle. and Chlorocyclopropane uis like this
Cl
|
CH
/ \
CH2-CH2
IIts the best i could do to draw you the structure
http://en.wikipedia.org/wiki/Cyclopropane
you can read here about it
its a little complicated here but you can try to understand:)
ohh okay
There are E and Z isomers, but not cis and trans because the groups are different.
WTF are cis and trans and E and Z?
I'm gonna spam my chemistry teacher's e-mail cause he never taught us SHIT! all he did was talk about catching moles in his backyard, what a nub!
how can you distinguish between the 5 isomers of c3h5cl? I found this question in a book and can't answer it :/ i'll appreciate any help
Post a Comment