The Student Room Group

double and single covalent bonds

OK, quick question.... do double covalent bonds produce a 'bend' in a chain of molecules?

I have a question asking why is a sulphur dioxide molecule V shaped when one of the oxygen molecules is double bonded to the sodium molecule, and one oxygen molecule is single bonded to an oxygen.

S=O-O

thanks
Reply 1
mchammer
OK, quick question.... do double covalent bonds produce a 'bend' in a chain of molecules?

I have a question asking why is a sulphur dioxide molecule V shaped when one of the oxygen molecules is double bonded to the sodium molecule, and one oxygen molecule is single bonded to an oxygen.

S=O-O

thanks


What do you mean by a "bend"?

And do you mean sulphur instead of sodium in your second question?
Reply 2
it depends on lone pairs. lone pairs of electrons give the V shape

i think
Reply 3
bean87
it depends on lone pairs. lone pairs of electrons give the V shape

i think


Yeah, i know, but in SO2, you have sulphur forming two double bonds to each of the two oxygen atoms, that means as S is in group VI, it has two electrons, meaning one lone pair left, unless, there is a dative covalent bond, which i couldn't think of.

I am not sure, but i think there is only one lone pair left in the sulphur, the bent shape is probably due to the lone pairs on oxygen repelling each other, so that they are as far as possible to minimise the repulsion.
Reply 4
this is what annoyed me about chemistry when i was doing it. it could have been due to my terrible teacher, but we never got taught definitive answers about the geometry of molecules. it was always a weak spot for me

i thought it was just due to the lone pair on sulphur causing a 120 degree angle
Reply 5
mchammer
OK, quick question.... do double covalent bonds produce a 'bend' in a chain of molecules?


No.
Reply 6
bean87
this is what annoyed me about chemistry when i was doing it. it could have been due to my terrible teacher, but we never got taught definitive answers about the geometry of molecules. it was always a weak spot for me

i thought it was just due to the lone pair on sulphur causing a 120 degree angle


It is best to draw out the dot and cross diagrams, you can see better how many lone pairs the sulphur would have after forming the double bonds, plus, if the sulphur does indeed have two lone pairs, the repulsion would produce an angle of roughly 105, similar to water(two LP on oxygen). Hmm, ask your teacher more about this then.
As the subject of sulphur (IV) oxide keeps coming up, here's an article about its structure:

http://www.ibchem.com/faq/what-is-the-structure-of-sulphur-iv-oxide/
Reply 8
shengoc
Hmm, ask your teacher more about this then.


i'm all done, no more A level chemistry for me.... ever! (hopefully :smile: )
Reply 9
bean87
i'm all done, no more A level chemistry for me.... ever! (hopefully :smile: )


You mean you are in uni already?
Reply 10
nay. gap year. sigh :frown:

can't wait till next sept
Reply 11
bean87
i'm all done, no more A level chemistry for me.... ever! (hopefully :smile: )


You mean you are in uni already?

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