Sciencemadness Discussion Board

Please tell me what this means:

Cornaboeaux - 21-9-2013 at 11:02

I'm a beginner amateur chemist, I know. I and don't know much yet. So could someone please tell me what the following sentence means: The top of the condenser is connected to a sulfuric acid trap which is connected to a gas absorption bottle.

So, why is this done exactly? And what does the apparatus look like? This is about a reaction that involves a reflux condenser and a mercury sealed stirrer.

elementcollector1 - 21-9-2013 at 11:36

Without knowing anything else, I would say that you have two gases being produced from the reaction, as well as water vapor. The mix is led into the sulfuric acid to capture the water, and led into something else to capture one of the gases.

bfesser - 21-9-2013 at 12:18

Quote: Originally posted by Cornaboeaux  
This is about a reaction that involves a reflux condenser and a mercury sealed stirrer.
I don't know of anyone who still uses mercury sealed stirrer cups. This is not a good idea. If you plan to actually carry out a reaction from the procedure you're reading, I'd suggest that you post the whole thing so we can advise you accordingly.

Wizzard - 21-9-2013 at 12:35

Phenyl acetone prep? I'm willing to gamble.

[Edited on 9-21-2013 by Wizzard]

Here's more about it

Cornaboeaux - 21-9-2013 at 21:11

Ok, this is the whole synthesis. You're right, it's phenyl acetone. It's taken from the rhodium site archive. This seems like the easiest method since I have access to all of the precursors. And I get it, it's probably dangerous as hell and everything. I'm aware of this and I'm going to use use fume cupboards, goggles and every possible safety gear if and when I'm going to try this. It's not like I don't have any experience in working in a lab. I've taken a few university cources, build all kinds of apparatus before and all that. This acid trap thing is just new to me. Why is it here?




41 grams (0.31 mole) of anhydrous aluminum chloride and 100 ml of anhydrous benzene (free from thiophene) were put in a 500ml three-necked flask which was equipped with a mercury-sealed stirrer, a reflux water condenser and a small addition funnel. The top of the condenser was connected to a sulfuric acid trap and this trap was connected to a gas absorption bottle. The mixture was stirred and heated to refluxing on a steam bath and 13.9 g (0.15 mole) of chloroacetone was allowed drop in slowly during a period of 30 minutes. After refluxing for 5 hours, the solution was practically black. After cooling to room temperature, the reaction mixture was decomposed by slowly adding water through the condenser, stirring during the addition. When no more hydrogen chloride was evolved, 20 ml of water and 20 ml of concentrated hydrochloric acid was added. The benzene layer was separated and the aqueous layer extracted with four 25 ml portions of benzene. All of the
benzene solutions were combined and filtered. The benzene was distilled off, and the remaining viscous oil was distilled under reduced pressure. Nine grams of liquid boiling below 123°C/20-22mmHg was obtained. Approximately 10g of high-boiling material was left in the distilling flask. Phenyl-2-Propanone was recovered from the distillate by making the bisulfite addition product, filtering, decomposing the addition product with sodium carbonate solution, and steam distilled as long as any oil distilled over. The distillate was extracted with ether, the ether dried over anhydrous MgSO4 and the ether distilled on a steam bath. The phenyl-2-Propanone was distilled under reduced pressure, bp 108-114°C/20-22mmHg. Yield 6.5 g (32%).

Nicodem - 22-9-2013 at 02:38

We do not tolerate the interest in chemistry due to greed. This forum is for those interested in science for amateur reasons only. It is obvious from your discourse that you care not about science or learning chemistry. Read the forum guidelines.