cis and trans dichloroethene

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

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Jacqueline Duong 1H
Posts: 61
Joined: Fri Sep 28, 2018 12:28 am

cis and trans dichloroethene

Postby Jacqueline Duong 1H » Sun Nov 18, 2018 3:32 pm

Can someone please explain cis-dichloroethene and trans-dichloroethene and what the difference between the two is?

Blake Salfer 1B
Posts: 30
Joined: Fri Sep 28, 2018 12:18 am

Re: cis and trans dichloroethene

Postby Blake Salfer 1B » Sun Nov 18, 2018 3:39 pm

Cis stands for same side dipoles and trans stands for different side dipoles. Because Cis-dichloroethane has dipoles on the same side the molecule is polar. The trans-dicholoroethane is non-polar because the dipoles cancel out on different sides.

Ester Garcia 1F
Posts: 29
Joined: Fri Sep 28, 2018 12:17 am

Re: cis and trans dichloroethene

Postby Ester Garcia 1F » Sun Nov 18, 2018 3:44 pm

Well first of all the polarity of the molecules are different: cis-dichloroethene is polar while trans-dichloroethene is non polar. The reason for this is the placement of the chlorine atoms within the molecule. In the cis-dichloroethene the chlorine atoms are on the same side of the carbon bond therefore the dipole moments do not cancel out creating a polar molecule. On the other hand, in the trans-dichloroethene the chlorine atoms are on different sides therefore the dipole moments cancel out resulting in a non-polar molecule. Looking at lewis structures of thee molecules would be really helpful in visualizing this :)

megansardina2G
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Joined: Fri Sep 28, 2018 12:23 am
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Re: cis and trans dichloroethene

Postby megansardina2G » Sun Nov 18, 2018 3:44 pm

Hi! The difference between cis-dichloroethene and trans-dichloroethene are the sides on which the chlorine atom is on. In cis-dichloroethene, both chlorine atoms are on the right side of the double bonded carbon atoms, whereas in trans-dichloroethene, one chlorine atom is on the left and one is on the right. When both chlorine atoms are on the same side (cis), the dipoles do not cancel and result in a polar molecule. However, when the chlorine atoms are on opposite sides (trans), the dipoles do cancel and the molecule is nonpolar. Sorry if this is hard to visualize, but I hope that helps!


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