Molecular Shape

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

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Steven Garcia 1H
Posts: 79
Joined: Fri Sep 28, 2018 12:16 am

Molecular Shape

Postby Steven Garcia 1H » Thu Nov 08, 2018 10:07 pm

If a molecule has a single central atom and three bonds for three other atoms (therefore three regions of high electron concentration), how do we determine whether this molecule has a trigonal planar-, trigonal pyramidal-, or t- shape?

Kessandra Ng 1K
Posts: 67
Joined: Fri Sep 28, 2018 12:25 am

Re: Molecular Shape

Postby Kessandra Ng 1K » Thu Nov 08, 2018 10:48 pm

The distinction between the 3 shapes you named are the number of lone pairs on the central atom, as the electron-electron repulsion by the lone pair of electrons will cause the other atoms to shift closer to each other; thus, the number of lone pairs on the central atom affects the shape of the entire molecule and the angles between each atom.

Trigonal planar: 0 lone pairs on the central atom

Trigonal pyramidal: 1 lone pair on the central atom

T-shaped: 2 lone pairs on the central atom.

404905747
Posts: 29
Joined: Fri Sep 28, 2018 12:17 am

Re: Molecular Shape

Postby 404905747 » Thu Nov 08, 2018 10:52 pm

Does this mean that you can determine the shape just by looking at how many lone pairs a molecule has?

Kessandra Ng 1K
Posts: 67
Joined: Fri Sep 28, 2018 12:25 am

Re: Molecular Shape

Postby Kessandra Ng 1K » Thu Nov 08, 2018 10:53 pm

This means you can determine the shape by looking at the number of atoms the central atom bonds to, and also the number of lone pairs of electrons on the central atom. Those are the 2 main factors in determining shape.

LeannaPhan14BDis1D
Posts: 57
Joined: Fri Sep 28, 2018 12:16 am

Re: Molecular Shape

Postby LeannaPhan14BDis1D » Fri Nov 09, 2018 9:18 pm

is there any other challenging molecule someone can provide as an example to help further help with my knowledge on how the shapes and angles work?


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