What exactly is Benzine?

TheBegotten

I'm asking for an information overload here, but could somebody please tell me what exactly is Benzene? My chemistry class is studying plastics and my techer couldn't explain it very well. Please make it so a 15 year old can understand it. If you cant then give it your best shot.

Professor_Fink

TheBegotten wrote: »

I'm asking for an information overload here, but could somebody please tell me what exactly is Benzene? My chemistry class is studying plastics and my techer couldn't explain it very well. Please make it so a 15 year old can understand it. If you cant then give it your best shot.

I'm not quite sure what you are looking for, but benzene is basically a ring of 6 carbon atoms, each of which has a hydrogen hanging off it. Because of the tight ring of atoms all of the same type, the bonds are a little unusual. What specifically do you want to know?

TheBegotten

I'm not quite sure what you are looking for, but benzene is basically a ring of 6 carbon atoms, each of which has a hydrogen hanging off it. Because of the tight ring of atoms all of the same type, the bonds are a little unusual. What specifically do you want to know?

That's brilliant thank you. I was looking at it in relation to polystyrene. It has an electron cloud due to the unused bond in each of its carbon atoms, it looks very unstable. And thanks for not being too complicated about it.

cianl1

TheBegotten wrote: »

That's brilliant thank you. I was looking at it in relation to polystyrene. It has an electron cloud due to the unused bond in each of its carbon atoms, it looks very unstable. And thanks for not being too complicated about it.

Not true there my young friend.

Benzene is a very stable molecule as a result of electron delocalisation. In other words the 6 pi electrons are spread across or "shared" among the six carbons, which is made possible through equidistant bond lengths. It's easiest to think of it as the double bonds alternating between carbons.

Sorry to get a bit technical but that's what happens.

If you haven't already, look at the Wikipedia page here: http://en.wikipedia.org/wiki/Benzene

Note the diagrams at the side at the beginning of the article, and try to get your head around the position of atoms/electrons/bonds in it. Then go down to "Structure" and look at the diagrams there. Benzene is best understood if you look at all the different ways of depicting it, but pay particular attention to the picture in the group under "Structure" labelled "delocalised pi system".

Build it up in your head. It might sound over-simplified but getting the structure into your head is half the battle.
1. 6 carbon atoms, each with a bond to the carbon on either side of it, forming a ring. Ring structures (generally) are strong. Each of these carbons have 4 electrons for bonding. If you're 15 I'm assuming you haven't done much detail of orbitals, so just take it that there's only 4 electrons free. Since each carbon has an electron shared with the carbons beside it, we've accounted for 2 electrons of each carbon.
2. 6 hydrogen atoms, each bonded to one of the carbons. Again this is a pretty stable bond. So we've accounted for 3 of the 4 carbon electrons.
3. The last electron of each carbon. This wants to make a second, or "pi" bond with one of the carbons on either side of it. But the two carbons on either side are equally good choices, so instead of three double bonds forming in the ring (in which case the carbon atoms would choose one other carbon to bond with and sort of be paired off 2+2+2), the electron becomes "delocalised", or contributed to an electron cloud which runs along the ring. Now, a double bond is stronger (not twice as strong) as a single bond, but to share the double-bondedness of each electron along the entire ring is even stronger. For something to react with it, it wouldn't just have to break a double bond, but would have to break the entire electron cloud.

So benzene is pretty stable. And sorry if I told you stuff you already knew but I figured it would be best to start from scratch.