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Why is CBr2Cl2 polar?

Posted: Tue Nov 19, 2019 11:34 pm
by Angeline 3E
Isnt CBr2Cl2 a tetrahedral and wouldnt the dipoles cancel out because if the Cl's are placed diagonally against each other the dipoles would cancel out same with the Br's? If they were placed diagonally, wouldnt the dipoles cancel out?

In:
https://www.google.com/imgres?imgurl=ht ... mrc&uact=8

sorrY i dont know how to put an image

Re: Why is CBr2Cl2 polar?

Posted: Wed Nov 20, 2019 12:25 am
by JOtomo1F
While the Lewis dot structure may look like its dipoles cancel out when you draw the two bromine atoms and two chlorine atoms diagonally, the shape tetrahedral is polar since it is asymmetrical. https://www.google.com/imgres?imgurl=https%3A%2F%2Fchem.libretexts.org%2F%40api%2Fdeki%2Ffiles%2F1314%2F204methane.gif%3Frevision%3D1%26size%3Dbestfit%26width%3D378%26height%3D261&imgrefurl=https%3A%2F%2Fchem.libretexts.org%2FBookshelves%2FInorganic_Chemistry%2FSupplemental_Modules_(Inorganic_Chemistry)%2FMolecular_Geometry%2FTetrahedral_Molecular_Geometry&docid=OUMd1jfcWiNIaM&tbnid=kPwQr5oQ5cr-iM%3A&vet=10ahUKEwiU173srvjlAhX0JTQIHbK3Bf8QMwh3KAAwAA..i&w=550&h=381&safe=strict&bih=569&biw=1280&q=tetrahedral&ved=0ahUKEwiU173srvjlAhX0JTQIHbK3Bf8QMwh3KAAwAA&iact=mrc&uact=8 I'm not sure how to put pictures but hopefully that worked lol. In that image, you can see the molecules are not directly across from each other in the tetrahedral shape and therefore, their dipoles would not cancel out.

Re: Why is CBr2Cl2 polar?

Posted: Wed Nov 20, 2019 12:28 am
by Alfred Barrion 2H
isn't CBrCl2 tetrahedral so its polar??

Re: Why is CBr2Cl2 polar?

Posted: Wed Nov 20, 2019 12:30 am
by Angeline 3E
JOtomo1F wrote:While the Lewis dot structure may look like its dipoles cancel out when you draw the two bromine atoms and two chlorine atoms diagonally, the shape tetrahedral is polar since it is asymmetrical. https://www.google.com/imgres?imgurl=https%3A%2F%2Fchem.libretexts.org%2F%40api%2Fdeki%2Ffiles%2F1314%2F204methane.gif%3Frevision%3D1%26size%3Dbestfit%26width%3D378%26height%3D261&imgrefurl=https%3A%2F%2Fchem.libretexts.org%2FBookshelves%2FInorganic_Chemistry%2FSupplemental_Modules_(Inorganic_Chemistry)%2FMolecular_Geometry%2FTetrahedral_Molecular_Geometry&docid=OUMd1jfcWiNIaM&tbnid=kPwQr5oQ5cr-iM%3A&vet=10ahUKEwiU173srvjlAhX0JTQIHbK3Bf8QMwh3KAAwAA..i&w=550&h=381&safe=strict&bih=569&biw=1280&q=tetrahedral&ved=0ahUKEwiU173srvjlAhX0JTQIHbK3Bf8QMwh3KAAwAA&iact=mrc&uact=8 I'm not sure how to put pictures but hopefully that worked lol. In that image, you can see the molecules are not directly across from each other in the tetrahedral shape and therefore, their dipoles would not cancel out.

Thank you !! I literally realized this was a tetrahedral right when you posted this

Re: Why is CBr2Cl2 polar?

Posted: Wed Nov 20, 2019 12:45 am
by Ashley Osorio
Can someone further explain this? I still don't understand how this is polar. No matter where the two Cl remain within the tetrahedral shape, the dipoles won't face the same way, so how can it be polar? Or is any molecule polar as long as their dipoles don't cancel????

Re: Why is CBr2Cl2 polar?

Posted: Sat Nov 30, 2019 8:39 pm
by JOtomo1F
Ashley Osorio wrote:Can someone further explain this? I still don't understand how this is polar. No matter where the two Cl remain within the tetrahedral shape, the dipoles won't face the same way, so how can it be polar? Or is any molecule polar as long as their dipoles don't cancel????


Yeah, if there are dipoles that don't cancel out completely then the molecule is polar.

Re: Why is CBr2Cl2 polar?

Posted: Sat Nov 30, 2019 8:57 pm
by sarahsalama2E
if all the atoms attached to the central are not the same, then the molecule is polar. As you can see in the tetrahedral diagram, the differing attaching atoms creates dipole moments, resulting in the atom being polar as a whole.

Re: Why is CBr2Cl2 polar?

Posted: Sat Nov 30, 2019 10:32 pm
by Melvin Reputana 1L
I would also like to add on that a good rule to follow is that in a tetrahedral, when all the terminal atoms are not the same, then the molecule is most likely polar. Even though, CBr2Cl2 looks like it is nonpolar, you also need to consider that terminal atoms are not exactly opposite from each other, so the pull that the atoms have will not be in the same direction due to the shape of the tetrahedral.