TBR Gen Chem - how do you draw HOCL and H3PO4?

[pfaction]

I mean the obvious way would be H-O-CL...but they have it drawn H-Cl=O? Am I wrong here, Wikipedia says it's H-O-Cl?

---

Members don't see this ad.

 

[folktale]

I mean the obvious way would be H-O-CL...but they have it drawn H-Cl=O? Am I wrong here, Wikipedia says it's H-O-Cl?

They probably mixed up Cl for a C. But the one I bolded is definitely wrong. It's H-O-Cl

 

[SaintJude]

Kaplan (& I believe Princeton) gives good rule of thumb: When drawing lewis structure, least electronegative atom that can satisfy octet rule will be central atom

 

[pfaction]

And how the **** is H3PO4, P is +3? DAFUQ?

 

[pfaction]

Kaplan (& I believe Princeton) gives good rule of thumb: When drawing lewis structure, least electronegative atom that can satisfy octet rule will be central atom

The way it's pictured:

H-CL=O

O takes a negative 2, CL takes a positive 2. Then H takes a +1, Cl takes a -1. Overall the charge is 0, but holy **** this is just awkward compared to H-O-CL, where everything seems much more natural.

 

[MedPR]

HOCl is all single bonds. If your image has a double bond it is an error. H3PO4 is a central P with three single bonds to OH groups and one double bond to an oxygen.

 

[MedPR]

Until you get a good intuition about drawing these, do it the long way by counting valence electrons, drawing them out one at a time, then connecting them to form bonds.

 

[pfaction]

No, I can draw them. TBR is just wrong. I'm posting a picture.

P question is in the middleish of the page.

 

[MedPR]

Oh, well then you have nothing to worry about. I can't see imgur at work.

 

[Dasypus]

HOCl is all single bonds. If your image has a double bond it is an error. H3PO4 is a central P with three single bonds to OH groups and one double bond to an oxygen.

This is exactly right about HOCl.

On the other hand, the confusion about the oxidation state of phosphorus in its acid is because sometimes posters have mentioned H3PO3 and sometimes H3PO4. The phosphorus acid with a +3 oxidation state is H3PO3, which is what it states in your passage. In phosphoric acid, H3PO4, P is +5, like you'd expect.

 

[pfaction]

Ah, my bad, I did misread H3PO3 as H3PO4. Am I right about HOCL in that picture at least?

 

[Dasypus]

I really don't know who dreamed up that H-Cl=O monster in the picture. It would never exist like that. OCl-, the hypochlorite ion, exists as a single-bonded molecule with the negative charge on the oxygen. When H+ adds, it adds where the negative charge is, forming H-O-Cl.

This isn't to say that Cl never forms double bonds; but it only does rarely (and, from what I can tell, only when multiple oxygens are around to soak up some of the electron density).

 

[MedPR]

Ah, my bad, I did misread H3PO3 as H3PO4. Am I right about HOCL in that picture at least?

Yea, HOCl should have 2 sigma bonds and 0 pi bonds.