Textbook Problem 2E. 19

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

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Alvin Lai 3J
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Joined: Wed Sep 30, 2020 9:55 pm

Textbook Problem 2E. 19

Postby Alvin Lai 3J » Sun Nov 22, 2020 8:12 pm

Predict the shapes and estimate the bond angles of (a) the thiosulfate ion, S2O32−; (b) (CH3)2Be; (c) BH2−; (d) SnCl2.

For (b), do you predict the shapes with the carbons as the central atoms?

Simrah_Ahmed1J
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Joined: Wed Sep 30, 2020 9:49 pm

Re: Textbook Problem 2E. 19

Postby Simrah_Ahmed1J » Sun Nov 22, 2020 8:25 pm

Actually in this problem part b you have to take Be as the central atom because you're not seeing the whole molecule written as C2H6Be, but it is written (CH3)2Be, so you are taking CH3 as methyl group not as separate Carbons and Hydrogens.
So you put aside the usual rule that you choose the central atom based on electronegativity of one atom, you are evaluating it as the electronegativity of the whole CH3 methyl group vs the Be. So in this case you will find that Be has to be the central atom in this molecule.

Lisa Wang 3B
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Re: Textbook Problem 2E. 19

Postby Lisa Wang 3B » Sun Nov 22, 2020 8:58 pm

(a) the thiosulfate ion, S2O32−; (b) (CH3)2Be; (c) BH2−; (d) SnCl2

for part b I like to think of it almost like 2 CH3's sandwiching the Be. So the central atom would be Be because of its low ionization energy. For part c Boron would be the central atom, and for part d Sn would be the central atom.

Bailey Giovanoli 1L
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Joined: Wed Sep 30, 2020 9:50 pm

Re: Textbook Problem 2E. 19

Postby Bailey Giovanoli 1L » Sun Nov 22, 2020 9:03 pm

I like to have in my mind that whenever I see parenthesis, I cannot separate the molecule. This will help when you begin to see more complicated formulas.


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