Hybridization in Light of Resonance

According to this video:


<http://www.youtube.com/watch?v=ns4Py96Bkn8&NR=1>


![enter image description here](https://i.stack.imgur.com/cgWJt.png)


1) Is this true? (You might recall I asked a similar question about $\ce{sp^2}$ hybridization implying $\ce{sp^2}$ hybridization for all directly linked atoms a while back, but I couldn't remember my prof's exact wording). I *think* this YouTube video is saying the same thing my prof said. 


2) Does this rule imply that both the oxygens in the below diagram are $\ce{sp^2}$ hybridized? Each is connected to an $\ce{sp^2}$ carbon atom. Each has lone pair(s).


![enter image description here](https://i.stack.imgur.com/owZLy.jpg) 


3) Even if we didn't know that the rule existed, we should still know that both oxygens are $\ce{sp^2}$ hybridized because of the following resonance possibility, correct? 


![enter image description here](https://i.stack.imgur.com/6zoOe.jpg)




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ETA: 


If the above is true then this doesn't make sense: 


![enter image description here](https://i.stack.imgur.com/pi5WS.png)





> 
> 1) Is this true?
> 
> 
> 


It's more or less true in the cases were hybridization methods \ techniques work. For example, when the hybridization of water is discussed it is often said that the central oxygen is more or less $\ce{sp^3}$ hybridized and therefor the two lone pairs on oxygen are in (roughly) $\ce{sp^3}$ orbitals. Current thinking based on photoelectron spectral data suggests that, instead of this traditional view, one lone pair appears to be in an orbital that is predominantly $\ce{P}$ and the other in an orbital that is predominantly $\ce{S}$. So hybridization models don't always give the correct answer. I'm not sure what the hybridization of an atom with a lone pair that's attached to a double bond really is. But it is probably OK to say what the teacher said in an introductory class in order to keep things simple for a while.



> 
> 2) Does this rule imply that both the oxygens in the below diagram are
>  sp2 hybridized?
> 
> 
> 


Assuming that the traditional hybridization approach is applicable here (e.g. is the ester oxygen behaving like water or is it "traditionally" $\ce{sp^3}$ hybridized?) then yes, both oxygens are roughly $\ce{sp^2}$ hybridized. Remember, hybridization is not a step function. There are hybridization indices between 2 and 3. 



> 
> 3) Even if we didn't know that the rule existed, we should still know
>  that both oxygens are sp2 hybridized because of the following
>  resonance possibility, correct?
> 
> 
> 


Some data on esters suggests that the $\ce{C-O-C}$ angle is around 115 degrees. Somewhat between 109 degrees ($\ce{sp^3}$) and 120 degrees ($\ce{sp^2}$). And maybe an intermediate hybridization is what we should expect based on the resonance structures for an ester.


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