Are moleculary geometry and shape different?  [ENDORSED]

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

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welcometochillis
Posts: 20
Joined: Fri Mar 17, 2017 3:00 am

Are moleculary geometry and shape different?

Postby welcometochillis » Mon Nov 20, 2017 12:30 am

From what i understand they seem to be the same thing, but other sources tell me they are distinctly different things that can sometimes be the same depending on the molecular structure? Could anyone clarify as to whether they are the same or not? And if they are different does one influence the other?

Lorie Seuylemezian-2K
Posts: 62
Joined: Fri Sep 29, 2017 7:04 am

Re: Are moleculary geometry and shape different?

Postby Lorie Seuylemezian-2K » Mon Nov 20, 2017 10:04 am

I believe they are different things. Molecular shape is the 3D structure of a molecule which includes the bond angles and the orientation of the different atoms. On the other hand molecular geometry is the name of the shape for example trigonal planar or tetrahedral.

Emma Miltenberger 2I
Posts: 51
Joined: Thu Jul 27, 2017 3:00 am

Re: Are moleculary geometry and shape different?

Postby Emma Miltenberger 2I » Mon Nov 20, 2017 12:12 pm

I believe they are the same thing. Molecular geometry and molecular shape are synonymous. However, there is a difference between electron geometry and molecular shape/geometry as molecular geometry/shape only considers bond arrangement and does not consider lone pairs.

soniatripathy
Posts: 50
Joined: Thu Jul 13, 2017 3:00 am

Re: Are moleculary geometry and shape different?  [ENDORSED]

Postby soniatripathy » Mon Dec 04, 2017 12:53 am

Molecular shape (also known as electron arrangement) considers the arrangement of bonds ignoring the lone pairs. It is simply based on the number or region of electron density. So an all central atoms with sp3 hybridization will have the same molecular shape of tetrahedral and all central atoms with sp3d2 will be octehedral, even if the number of bonded and lone pairs is different. On the other hand, molecular geometry takes into account the number of lone and bonded pairs. For example CH4 and NH3 both have 4 regions of electron density BUT CH4 has 4 bonded pairs and 0 lone pairs so it has an molecular geometry of tetrahedral but NH3 has a molecular geometry of trigonal pyramidal since it has one lone pair and 3 bonded pairs. One important note is that the name for molecular shape and molecular geometry will be the same when there are no lone pairs.


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