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

Moderators: Chem_Mod, Chem_Admin

Posts: 98
Joined: Sun Sep 15, 2019 12:15 am


Postby Andrea_Torres » Sun Nov 17, 2019 6:20 pm

How does repulsion help influence the molecular shape?

Aarja Pavade 1H
Posts: 103
Joined: Sat Aug 17, 2019 12:18 am

Re: Repulsion

Postby Aarja Pavade 1H » Sun Nov 17, 2019 6:22 pm

Repulsion influences the molecular shape as it can force bonding electrons closer together, reducing their bond angle. For instance, a molecule with a tetrahedral shape has bond angles of 109.5 but once lone pairs are introduced, there is greater repulsion and the bond angles decrease to <109.5 with a shape of trigonal pyramidal or bent.
Last edited by Aarja Pavade 1H on Sun Nov 17, 2019 6:25 pm, edited 1 time in total.

Posts: 101
Joined: Sat Sep 14, 2019 12:17 am

Re: Repulsion

Postby Jiyoon_Hwang_2I » Sun Nov 17, 2019 6:24 pm

Usually, lone pairs cause more repulsion, so the bond angle decreases. For example, NH3 has 1 lone pair on nitrogen and its bond angle is 107 degrees, but H2O has 2 lone pairs and the bond angle is 104.5 degrees. So, the more lone pair electrons on the central atom, the more repulsion, causing the bond angle to decrease.

Return to “Determining Molecular Shape (VSEPR)”

Who is online

Users browsing this forum: No registered users and 4 guests