BF2S Forums THIS IS DRIVING ME INSANE! AS Chemistry - help!

ATG wrote:

1. Each C has 1 P orbital?   no 
2. Each of these P orbitals has 2 electrons in it?     yes 
3. Each C has 1 S orbital involved in bonding (i know there is 1S, 2S)?     no, it's 3s 
4. Each of these S orbitals has 2 electrons in it?     false 
5. What does the 1S orbital do? In the case of Ethene, is it involved in bonding the H atoms?    it's the binding agents catalyst 
6. Someone PLEASE label where all the electrons are! Total i count 2 x 2 in S oribitals + 2 x 2 in P orbitals = 8 electrons in this covalent bond. But in a double covalent bond only 4 are shared?!    dood, you expect me to do all your work for you?   pfft. 

1. No? So how many per P orbital? I thought it was 2P2?
2. K
3. Huh?! Carbon is 1S2, 2S2, 2P2? Where the 3?
4. Again, 1S2, 2S2? How many then?
5. I have no idead what you just said! / fails at chemistry. Which electrons bond to the H on ethene?
6. If you were my e-hero you would... This is what i am most confused about as well... how the orbitals relate to the electrons.

BTW this is not Homework, its just extra work im doing to work on my understanding.

orbital notation of carbon = 1s2 2s2 2p2

Ethene hybridizes as sp2 2p

Personally I think you are being taught very very much out of order if you do not know which orbits are which and how many electrons are in them when you are trying to do pi and sigma bonds...

I think looking at what ATG said, he is getting confused because two of the p orbitals merge with the s to form the sp2 orbit which forms the 4 sigma bonds, while one p orbit remains which makes the pi orbit.

Last edited by SilentscoutIX (2007-05-29 17:39:13)

=Karma-Kills= wrote:

Yeh, tbh chemistry is a joke.

I got the chemistry prize in my school at GCSE (for being best at chemistry in the year) A* at GCSE, and now the whole AS Chem set has been getting C,D,Es

Weve never been taught binding agents or hybridizing! / dispear.

I think im starting to get it now though.

Please check this head rambling...

1S2, 2S2, 2P2.

Only 2S2 and 2P2 are involved in bonding.

Per Carbon, 1 S electron is used to make a sigma bond,
                  1 P electron is used to make a pi bond

The spare 1 spare S and 1 spare P electron per Carbon are used in bonding to hydrogen?

I may have chose a bad example with Ethene, as this hybridizes sounds complicated.

Does my thinking hold for just a C=C bond then?

You are correct except for you last statement, and you need to know hybridization in order to really understand this stuff sorry to tell you. I am willing to help you as best as I can seeing as this is stuff I was literally learning today and for the past two weeks so its fresh in my mind. That being said idk how I would explain hybridization over a forum.

Thanks - i was ready to rip my head off - atleast im getting closer now.

Can i ask what you are studying? A Level? I notice you are from Canada, so equivilent AS or A2? Im studying AS in UK, and am hoping i dont know hybridization becuase its not on my course. TBH this is only a very small section (usually its like a 3 mark question "Draw and describe a C=C bond" in past papers) but i wanted to be sure of it.

By my last statement do you mean "The spare 1 spare S and 1 spare P electron per Carbon are used in bonding to hydrogen?"

So i am correct in thinking:
Per Carbon, 1 S electron is used to make a sigma bond,
                  1 P electron is used to make a pi bond

^^ That was my Eurka moment

To clarify, 1P oribital (with 1 electron) + 1P oribital (with 1 electron) = 1 Pi Bond?
               1S orbital (with 1 electron) + 1S oribital (with 1 electron) = 1 Sigma Bond?

See 1337 paint drawing...

Is that *kinda* correct? (1 red dot = 1 electron)



EDIT:

justice wrote:

"hybridization" isn't in the AS sylabus (doing OCR?) so don't worry about that.

LOVE YOU
Yes im doing OCR - phew.

Yeh past papers FTW, the only thing is, i looked at chains and rings papers and realised i had no idead (foundation is fine tho) so i thought id make some notes first... and then all this started!

Last edited by =Karma-Kills= (2007-05-29 17:57:34)

Yup chains and rings is the toughest, because they can ask a lot of different stuff, it's not as concrete. But do well on how far how fast and foundation you'll do good. How are your calculations, if they're good that make how far how fast even easier.

ReDevilJR wrote:

Wow, this is confusing,

Tell me about it

justice wrote:

Yup chains and rings is the toughest, because they can ask a lot of different stuff, it's not as concrete. But do well on how far how fast and foundation you'll do good. How are your calculations, if they're good that make how far how fast even easier.

Chains and rings: Hate mechanisms, too many bloody conditions and catalysts, free radicals are iffy.
Foundation: Fine - actually quite like it.
Calculatations: Normally pretty easy, but some times % purity takes some thinking.
How Far, How Fast: Doable, but needs some work.

What I hate MOST are those voltaic cells/electrolytic cell shit! Where two metals react...

=Karma-Kills= wrote:

ReDevilJR wrote:

What I hate MOST are those voltaic cells/electrolytic cell shit! Where two metals react...

I dont do that! - i hope anyway, cos ive never heard of it!

Im in England, doing my exam on June the 9th (or 6th) i think.

Yep 6th, I've been halping my nephew prepare, he's shit scared :p

One more thing,

Alkanes are soluble in...?
Alkenes are soluble in...?

Thanks

=Karma-Kills= wrote:

ATG wrote:

1. Each C has 1 P orbital?   no 
2. Each of these P orbitals has 2 electrons in it?     yes 
3. Each C has 1 S orbital involved in bonding (i know there is 1S, 2S)?     no, it's 3s 
4. Each of these S orbitals has 2 electrons in it?     false 
5. What does the 1S orbital do? In the case of Ethene, is it involved in bonding the H atoms?    it's the binding agents catalyst 
6. Someone PLEASE label where all the electrons are! Total i count 2 x 2 in S oribitals + 2 x 2 in P orbitals = 8 electrons in this covalent bond. But in a double covalent bond only 4 are shared?!    dood, you expect me to do all your work for you?   pfft. 

1. No? So how many per P orbital? I thought it was 2P2?
2. K
3. Huh?! Carbon is 1S2, 2S2, 2P2? Where the 3?
4. Again, 1S2, 2S2? How many then?
5. I have no idead what you just said! / fails at chemistry. Which electrons bond to the H on ethene?
6. If you were my e-hero you would... This is what i am most confused about as well... how the orbitals relate to the electrons.

BTW this is not Homework, its just extra work im doing to work on my understanding.

I was JOKING!!!

Lol i was looking more along the lines of Organic / Inorganic solvent...

CoronadoSEAL wrote:

=Karma-Kills= wrote:

Lol i was looking more along the lines of Organic / Inorganic solvent...

are those my two choices?
  *flips coin*
inorganic

You flipped wrong

Alkanes and alkenes are both soluble in organic solvents as they are both non-polar, hence soluble in organic non-polar solvents.

As far as the diagram at the beginning goes, SilentScout is right, the diagram's wrong. The orbitals will hybridize (mix together) to make something quite different to that picture. If we're going to ignore hybridization, when looking at orbital notation 1s2 2s2 2p2 etc. remember that any full shells will play no part in bonding. In the case of carbon the first shell is complete hence the two electrons in the 1s2 orbital will do nothing but sit there. This leaves 4 electrons to make carbons 4 bonds. In the example od Sodium 1s2 2s2 2p6 3s1 the '1' shell and the '2' shell are complete so only the electron in the 3s1 is available for bonding.

Please clarify,
1. Each C has 1 P orbital?
2. Each of these P orbitals has 2 electrons in it?
3. Each C has 1 S orbital involved in bonding (i know there is 1S, 2S)?
4. Each of these S orbitals has 2 electrons in it?
5. What does the 1S orbital do? In the case of Ethene, is it involved in bonding the H atoms?
6. Someone PLEASE label where all the electrons are! Total i count 2 x 2 in S orbitals + 2 x 2 in P orbitals = 8 electrons in this covalent bond. But in a double covalent bond only 4 are shared?!

I really need some to physically show me where all the electrons are in the orbitals and how they add up (eg 6 electrons per carbon, 4 electrons shared, 2 used in bonding to H per C).

1. Each carbon atom has 3 p orbitals, they are the figure of 8 shaped orbitals. They have one sitting on each x,y,z axis, so one going above and below the carbon atom, one left and right and one sticking into and out of the screen

2. WHEN FULLY BONDED each p orbital has 2 electrons in it. carbon alone only has 2 electrons it can put in the three p orbitals, so only one is filled (assuming we're ignoring hybridization). To fill the rest, the atom forms bonds with other atoms and shares electrons, thereby getting to the desired 6 electrons to fill all three p orbitals

3. the 1s orbital is a completed shell hence it plays absolutely no part in bonding, the 2s orbital is in an incomplete shell hence they can be used for bonding.

4. correct, also they look like a sphere.

5. the 1s orbital does nothing. Carbon makes 4 bonds using 4 electrons, 2 from the 2s and 2 from the 2p.

6. In your diagram, there are 2 electrons in each bond, so the two p orbitals that are interacting to make a pi bond will have 1 electron in each making a total of 2 electrons in the pi bond. The sigma bond (the green bit) will have again one electron from each carbon in, so two electrons in the whole thing. That's 4 electrons making 2 bonds between the two carbons. Each carbon also has 2 electrons in the 1s orbital that are doing nothing and presumably 2 electrons making bonds to two hydrogen atoms although this isn't shown.

It's kind of hard to know if that's the sort of answer they're after as the initial diagram is wrong as you will learn if you do a degree in chemistry (which I thoroughly recommend).