Horza2002

Mississippichem has given you some great advice there. And remember that bromine is a lot larger than chlorine so its nucleophilic properties are different to that of chlorine

a. Remember that enantiomers are inseperable in achiral enviroments but are different in chiral enviroment (like the body) b. Conformers are how the molecule folds up in 3D space...how might the shape of a molecule be important in the body (think proteins) c. This also referes to the shape of molecules...but since they have different configurations, it is far more important than b

As UC says, the first step is a Mitsunobu reaction that is used to form the arly-alky bonds. The second step is a Stephen reduction using tin(II) chloride. Its not really used anymore because there are more efficient ways to do it...commonly you'd use hydrogen gas with palladium/carbon. However, in this case, the alkenes would also be reduced with hydrogen with Pd/C

The algea do NOT generate electrons. The electrons are already there, they are just excited to a state where they become accessible for capture and use. In chlorophyl, I think the electrons are excited out of a magnesium atom before being captured and used to drive further reactions

No I don't beleive ion stuff that I can't see, there are wonderful techniques that you can use to give DIRECT evidence that you have your molecule. If you'd actually studied chemistry, you'd know that IR, UV, NMR, microwave and X-Ray spectroscopy all provide DIRECT evidence that you have a molecule which you can't see. And read my post correctly, and you'll see that I said you can't see molecules reacting in solution! That link and all other pictures of moclues come from a molcules being loaded onto a solid surface! I.E. not in solution!

Im no expert on SDS pages only having done a couple....but I have had the problem that my protein degraded after purification and so I ended up with lots of bands in the individual lanes.

Cabinintheforest, did you bother to read the posts? If you think direct evidence is a video, then how do you respond to the entire subject of chemistry? You can't see individual molecules in solution reacting together. I am at the moment doing a Suzuki reaction; I can't see my aryl bromide molecule inserting into the palladium-phosphine bond and then my boronic acid coordinating and my biaryl product being released.....but funnily enough, I now have a pile of beautifully red crytals of MBC sitting in fumehood drying....but as i couldn't see MBC being put together, obviously I havn't made anything.....

There is no reaction in which u can mix a set amount of reagents together and they will continuously produce heat. You can have several reactions going on one after the other that release heat, but you will eventually reach a point where the products are too stable to go any further. The maximum amount of energy a reaction can possible liberate is achieved by breaking all the bonds and making the strongest ones possible. Once thats done, the products will be the most stable possible and will therefore be no further reaction. Like Mississippichem said, there are some living polymerisation radical reactions that can go on in practise for eternity if you provide enough reagents for them. But then, you have to keep putting reagents in and it requires energy to yields them in the first place.

The difficulty also arises with what to do with the CO2 once you've captured. There is alot of research into using to the make plastics by reacting it with epoxides and zinc BDI catalysts. The major problem with using CO2 as a reagent is that it is extremely stable with respect to chemical processes and the entropic loss of losing a gaseous molecule.

Sounds like a homework question...so I'll give you a little help. Whats the equation for calculating concetration? How many protons does sulphuric acid release in water?

Yes they certainly deserve the NObel prize..these reactions are extremely useful; espeically in making biaromatic systems whihc is very difficult otherwise. With that said, palladium is becoming more and more expensive not to mention the trouble you have to go through to get it out and the end of your reaction. Once the next batch of solid-supported palladium reagents come out these reactions will be the new Wittig!

You normally get dangling bonds. http://en.wikipedia.org/wiki/Dangling_bond The outer atoms tend to hybridise differently so that they can form the required number of bonds

The sulphuric acid is there purely to provide a proton to catalyse the reaction. Any acid strong enough to protonate formic acid will work. HCl might not be strong enough but there are some others that would also do nicely. It would mainly depend on what the rate determining step was. However I dont think it'l be an E2 reaction. The elimination of water is probally the rds in which case this would be an E1 reaction as there is only one molecule involved in the rds.

Adding to what mississippichem said, you can then collect the hydogen has given off in a stoppered test tube and put a lighted splint in to give you a small explosion of hydrogen. And it squeaks loudly...always fun. If you have a fumehood in the lab then you could always try the volcano experiment. Use a magnesium flare to ignite a small pile of ammonium dichromate (which is bright orange). Then sit back and watch a mini volcano in your fumehood as large amounts of nitrogen gas are released (see video below). If you do that, then I must stress you ONLY do it in a fumehood (unlike in that video) seeing as ammonium dichromateis VERY VERY toxic and explosive; properly best if you let your teacher do it.

I've just had a very quick look at it and heres what I came up with. Sulfuric acid pronates and then eliminates the water to leave you with prononated CO. This is simply deprotonated by the water you just eliminated to give you the CO untitled.bmp

While reducing and oxidising the acetone might give you good seperation, its not exactly enviromentally friendly. If you've got a large amount of the mixture to seperate then you're going to be using a large amount of metals to do this reaction. If you're then planning on reusing the solvents for more reaction, you'll have to spend lot of time and money extracting the remaining metal to levels that are acceptable. Not to mention you would then have to dispose of the waste metals properly. Pyridinium chlorochromate is also very toxic and difficult to handel safely on a large scale. If you want to use metals to do it, then you could use a co-oxidant to regenerate the reaction species but that would require using stoichemtric amounts of something else. Hydrogen peroxide is a common one but can react with your solvent to give some rather nasty products.

Exo essentially means leaving Endo essentially means receiving Thermic refers to heat So, exothermic means heat leaves the reaction (and will therefore fell hot) while endothermic heat enters the reaction (and will therefore feel cold). As Mr Skeptic has said, the enthalpy will tell you whether a reaction is exo or endo. In general, reactions that are neither exo or endothermic tend to be isomerisations.

Insane Alien, whats the difference? I was always taugh in geography that fault lines and tectonic plate boundaries are the same thing.

If its a mixture then the best way will be to distil the mixture. Acetone boils at 56oC while chloroform boils at 61oC. Might be a little tricky to keep the temperature at around 58oC but that should work

Unless I'm mistaken, the UK s not on any fault lines, its in the middle of a plate. So I guess the tremors must be passed through the plate until it gets here.

Well acetone mixes with water while chlroform doesn't. Addinf a small amount of water should allow you to seperate them and then dry the acetone again; never tried that so might work. Distillation would be the best way to do it. Are you mixing waste chloroform and acetone together then? Halogenated waste solvents should be kept seperate as it needs different precaution and methods to deal with it

Sorry yes I meant to say that they are more common at fault lines since we do get earthquakes here in GB.

It may seem odd that it is the antidote, but alcohol is the antidote to drinking antifreeze.

I think some of your confusion is arising from the fact you want to see individual species evolving. Evolution says that there is a gradual change from one to another..you don't wake up one morning to find you'r child is a different species. Also remember, the idea of grouping individuals together is not natural..it is something that we humans do to try and make sence of things. There are many accounts of fossil remains of animals being debated for years over which species they belong too. Some people think that this is evidence against evolution but they are wrong...the fact that this indivdual shows characterisitcs of both species IS proof of evolution..he/she/it is obviously a halfway point between the two species......remember grouped species are humans attempt to explain things! One of the defintion of a species is that they can not reproduce to give fertile offsrping. Horses and donkeys can reproduce to give an offspring in rare cases but this child is infertile...therefore horses and donkeys are different speices. The problem is often that they are infertile. They are as similar to each other as horses/donkeys, but different enough that they can't reproduce.

Your right so far in that earthquakes only occur at fault lines (i.e. where plates meet). If I remeber rightly, earthquakes are not caused by collisions of the plates. Earthquakes occur when plates are moving past each other (parallel sort of) in opposite directions. The friction can stop them from moving and they get stuck. This carries on until one plate suddenly slides past the other which is then the earthquake. Plates colliding (i.e. moving towards each other) is what creates mountains. One plate is forced up and over the other causing it to move upwards. Plates moving away from each other is where you tend to get volcanoes because there is a gap that allows magma to reach the surface.