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

ATG wrote:

I was JOKING!!!

Chemistry. Serious business.

I will believe what anyone says anything about chemistry as i have no knowledge whatsoever to say otherwise!

PureFodder wrote:

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

Thanks. But what about something like haloalkanes (e.g with C-Cl bonds) - these are polar right? And so will dissolve in polar solvents?

PureFodder wrote:

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.

"Remember that any full shells will play no part in bonding" - by this do you mean shell as in 1st Shell, 2nd Shell or orbitals? Im asumming both? As anything that is full and stable wont need to react... right?

I think i picked a very bad example with ethene...

PureFodder wrote:

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

Yes, but there are only 2 electrons in p orbitals. So isnt it something like 2P1X, 2P1Y, 2P0Y. By there being an empty oribital, arent there in effect only 2? I see where your coming from, but isnt it like saying, its got 3P6 as well... just empty?

PureFodder wrote:

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

Yeh. It fills one at a time first though, correct?

PureFodder wrote:

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.

Yep!

PureFodder wrote:

4. correct, also they look like a sphere.

Cool.

PureFodder wrote:

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

Got it! The 2S and 2P bonds being Pi and Sigma bonds?

PureFodder wrote:

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.

Wehay i understand. I was assuming 2 electrons per orbital, so therefore 2 x 2 = 4 electrons per each bond. I see my mistake.

Thanks so much for the amazing input.

+1 to my new e-hero.

Muhahaahahahahahahahahaha!!!!! AS Chemistry subject of the devil! All i can say is dropsies.