cis and trans

(Polar molecules, Non-polar molecules, etc.)

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704992521
Posts: 31
Joined: Fri Apr 06, 2018 11:05 am

cis and trans

Postby 704992521 » Sun May 27, 2018 11:06 pm

Can someone explain what professor Lavelle was talking about in lecture with the whole cis and trans molecules.

204750609
Posts: 18
Joined: Fri Apr 06, 2018 11:02 am

Re: cis and trans

Postby 204750609 » Sun May 27, 2018 11:10 pm

A cis isomer is polar and a trans isomer is non polar.

Vivian Gonzalez 1A
Posts: 30
Joined: Fri Apr 06, 2018 11:03 am

Re: cis and trans

Postby Vivian Gonzalez 1A » Sun May 27, 2018 11:12 pm

In lecture, the polar molecule we were using as an example was cis-dichloroethene. The cis just means that the two chlorine atoms were on the same side giving the molecule its polarity. On the other hand, there was also trans-dichloroethene where the chlorine atoms were on opposite sides and so the polar bonds with dipole moments cancelled each other out making it non polar.

304984981
Posts: 28
Joined: Fri Apr 06, 2018 11:05 am

Re: cis and trans

Postby 304984981 » Sun Jun 03, 2018 2:34 pm

cis molecule has same types of atoms on the same side.
trans molecule has same types of atoms on the opposite sides.
So, even the polar bonds exists, but the trans molecule is non-polar in general since they oppositely arranged atoms' dipole moments cancel out.

Ziana Bhanji 1E
Posts: 30
Joined: Fri Apr 06, 2018 11:01 am

Re: cis and trans

Postby Ziana Bhanji 1E » Sun Jun 03, 2018 2:46 pm

Also remember that the van der Waals dispersion forces between the molecules will be identical in both cases

Sarai Ventura 1L
Posts: 30
Joined: Mon Apr 09, 2018 1:39 pm

Re: cis and trans

Postby Sarai Ventura 1L » Sun Jun 03, 2018 4:32 pm

The main difference between the two is that the cis isomer is a polar molecule whereas the trans isomer is non-polar. Both of the isomers have exactly the same atoms joined up in exactly the same order. That means that the van der Waals dispersion forces between the molecules will be identical in both cases.

004985802
Posts: 27
Joined: Fri Feb 02, 2018 3:00 am

Re: cis and trans

Postby 004985802 » Sun Jun 03, 2018 8:39 pm

cis molecules have side groups of atoms on the same side of a molecule whereas trans molecules have groups on opposite sides of the molecule

Tiffany Tufenkjian 1E
Posts: 30
Joined: Fri Apr 06, 2018 11:05 am

Re: cis and trans

Postby Tiffany Tufenkjian 1E » Sun Jun 03, 2018 8:56 pm

In a cis- molecule the dipoles will not cancel, while in a trans- molecule the dipoles will cancel.


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