Isomers E/Z

username459260

http://s359.photobucket.com/albums/oo40/jsmith613/?action=view&current=Chem-2.png

Is this an E or Z isomer

Z isomer

Z, I think :smile:

E = Entergan = Together

and Z = Zusaman = Apart.

Reply 3

Susanne839

I would say it's an E isomer as the carbon chains are opposite each other about the double bond.

Reply 4

charllysaur

it is an E/Trans isomer.

Reply 5

xXxBaby-BooxXx

Original post by RFextra

Z, I think :smile:

E = Entergan = Together

and Z = Zusaman = Apart.

It's E. The Z means "together" and the E means "opposite"

I always remembered it because Z is almost like an S, and same begins with an S

(yes I am a little bit special :colondollar:

)

Reply 6

thegodofgod

Original post by RFextra

Z, I think :smile:

E = Entergan = Together

and Z = Zusaman = Apart.

Other way around dude:

E - Entgegen - opposite

Z - Zusammen - together

Reply 7

FadeOut101

it's E-2-chloropent-3-ene
a trans isomer (or E isomer)

Reply 8

Steven

My teacher always said this to me:

Z - Ze same side (in a french accent :rolleyes:

). The two CH3 groups aren't on the same side so I'd say E-isomer.

Reply 9

charllysaur

Original post by RFextra

Z, I think :smile:

E = Entergan = Together

and Z = Zusaman = Apart.

That's the wrong way round, zusammen means together
And entgegen means opposite :smile:

Reply 10

thegodofgod

Original post by xXxBaby-BooxXx

It's E. The Z means "together" and the E means "opposite"

I always remembered it because Z is almost like an S, and same begins with an S

(yes I am a little bit special :colondollar:

)

Yh - my chemistry teacher remembers Z as "On zee zame zide" (like how a Dutch person would say "On the same side")

Reply 11

charllysaur

Remember it, as they're on Zee same side ^^;
and if they are on the same side, they are cis-ters :P

Reply 12

thegodofgod

Finally - some German came in use :biggrin:

Reply 13

EierVonSatan

Original post by FadeOut101

it's E-2-chloropent-3-ene
a trans isomer (or E isomer)

Where did you get 5 carbons from? :p:

It's Z-2-chlorobut-2-ene :smile:

Original post by Steven

My teacher always said this to me:

Z - Ze same side (in a french accent :rolleyes:

). The two CH3 groups aren't on the same side so I'd say E-isomer.

That's not how E/Z assignments work, you need to look at the two heaviest atoms joined to the double bond first. So the two heaviest (first) atoms are chlorine and carbon which are on zee zame zide :smile:

Reply 14

cpchem

Original post by EierVonSatan

Where did you get 5 carbons from? :p:

It's Z-2-chlorobut-2-ene :smile:

I was scrolling down this thread despairing at the lack of knowledge of the rules of Messrs Cahn, Ingold and Prelog. Your post saved what remains of my sanity. Eternal thanks.

:tongue:

Reply 15

username459260

ok, so the answer was E isomer

However, if we rank the groups attached to the two central carbon atoms we get

12__17
__C=C
1___12

Therefore, the highest ranks are on the same side which SHOULD make them Z isomers BUT THEY ARE NOT

Please xplain

IGNORE the _

Reply 16

cpchem

Original post by jsmith6131

Listen to EVS, and not the others. If the mark scheme for said question says that the molecule you showed us is the E isomer, it is wrong and was written by idiots.