Bonding?

[m@tty]

How does Sulfur support 6 bonds in sulfuric acid?? It only has two vacancies in it's valence shell, and I thought this meant that there could be a maximum of two bonds, so how does the bonding in cases such as this work?

[qshyrn]

i think the O's (which are joined to H) have -1 charge, and S has -2 charge
not sure tho

[vexx]

The oxygens definitely are in the -2 oxidation state.

I'm pretty sure the sulphate can take form in a +6 oxidation state thereby forming 6 bonds.

[Edmund]

The oxygens definitely are in the -2 oxidation state.

I'm pretty sure the sulphate can take form in a +6 oxidation state thereby forming 6 bonds.

Yes, +6 is a common oxidation state for sulfur.

[m@tty]

Are you sure it is in that structure, Simon? I got this structure from a Google images search, and they were all like that.... Also, my teacher referred to the structure I posted :S

The oxygens definitely are in the -2 oxidation state.

I'm pretty sure the sulphate can take form in a +6 oxidation state thereby forming 6 bonds.

What does having an oxidation state of +6 mean fundamentally?

[qshyrn]

i think simons structure is wrong (sorry lol) do a search on google for structure of sulfuric acid

[vexx]

Are you sure it is in that structure, Simon? I got this structure from a Google images search, and they were all like that.... Also, my teacher referred to the structure I posted :S

The oxygens definitely are in the -2 oxidation state.

I'm pretty sure the sulphate can take form in a +6 oxidation state thereby forming 6 bonds.

What does having an oxidation state of +6 mean fundamentally?

It's an indication of how many electrons lost or gained from the original 'state' or electrons it had.
So Sulfur is +2, and with an increased oxidation state it can have 6 more electrons to make the octet, therefore being able to form double bonds with two oxygens and single bonds with other two. That what you asked?

[simonhu81292]

of then .. thanks !!!

[m@tty]

It's an indication of how many electrons lost or gained from the original 'state' or electrons it had.
So Sulfur is +2, and with an increased oxidation state it can have 6 more electrons to make the octet, therefore being able to form double bonds with two oxygens and single bonds with other two. That what you asked?

So two of the filled orbitals were broken and four electrons released to allow the extra bonds? So there will only be one lone pair remaining?

Also, is there the potential for all electrons to form a bond? So this sulfur could make 8 bonds? Or oxygen could make 8 bonds under some conditions?

[kyzoo]

Also, is there the potential for all electrons to form a bond? So this sulfur could make 8 bonds? Or oxygen could make 8 bonds under some conditions?

Nah, Oxygen will only change oxidation number (from -2) when it is bonded to fluorine or in certain molecules such as peroxide.

Electronegativity is kind of a measure of the "priority" a particular element has in having its "default" oxidation number, a measure of the ability of an element to maintain its "original resolve" in the face of adversity.

Only fluorine is more electronegative than oxygen. So unless oxygen is bonded to fluorine, oxygen will never lose electrons to any other element it has bonded with, so it will never have a positive oxidation number (unless bonded to F). Oxygen cannot have an oxidation number of less than -2 since it cannot gain more than 2 electrons (gain 2 electrons = full valence shell).

[m@tty]

Thanks, but, I know that. It's oxidation number only changes when bonded to itself or Fluorine.

So would it be possible to synthesise ? Rendering O an oxidation state of 6+ ?

And wait, I think I realise the flaw in my reasoning above.. S only has 6 valence electrons, so it can only form 6 bonds. For some reason I was thinking there were three lone pairs and two electrons :S

So with sulfur in sulfuric acid there are 6 covalent bonds, so that means 12 electrons. Doesn't this mean that you count all 12 of these as belonging to sulfur ? As in the case of CO₂ carbon contributes four electrons and each oxygen contributes two, and you count each as having all electrons involved in bonding. SO with sulfur what happens with these twelve bonding electrons? You can't say that it has 12 valence electrons, can you ? :S

Thanks.

[Mao]

So with sulfur in sulfuric acid there are 6 covalent bonds, so that means 12 electrons. Doesn't this mean that you count all 12 of these as belonging to sulfur ? As in the case of CO₂ carbon contributes four electrons and each oxygen contributes two, and you count each as having all electrons involved in bonding. SO with sulfur what happens with these twelve bonding electrons? You can't say that it has 12 valence electrons, can you ? :S

Actually, you can. You end up having electrons expanding from the 3p orbitals to occupy 3d orbitals, hence expanding the capacity of the valence shell. [For those who know about VSEPR, two electrons from the p orbital go into d_x^2-y^2 and d_z^2, and forms a spd2 hybridization (4 coordinate), and the two remaining p orbitals then form 2 pi-bonds to two of the oxygens, but as we all know hybridization don't actually happen, but here's the gist of it]

So this should answer your next question: OF6 can't be formed, since it is in the second period and can't expand into unfilled d orbitals (there's no 2d orbital).