Die Suche ergab 23 Treffer
- Dienstag 26. Dezember 2017, 19:24
- Forum: Laborgeräte
- Thema: Claisen adapter NS29 ?
- Antworten: 7
- Zugriffe: 3617
I think it should at be possible to get your money back via your bank. At least for a while after you payed it. Edit: I've also ordered there two times, the first time everything was fine but the second time nothing happened, they didn't answer my e-mails and I didn't get anyone on the phone. Lucki...
- Mittwoch 20. Dezember 2017, 00:06
- Forum: Laborgeräte
- Thema: Claisen adapter NS29 ?
- Antworten: 7
- Zugriffe: 3617
I think that will even take longer than one month if you order at Laborhandel Krumpholz. Or anything have changed? ;) I did pay my order more then one month ago and didn’t received any order yet. Is there no customer protection in Germany/Europe? What a nightmare! No communication: Email (multiple ...
- Sonntag 26. Juni 2016, 13:29
- Forum: Laborgeräte
- Thema: Claisen adapter NS29 ?
- Antworten: 7
- Zugriffe: 3617
Claisen adapter NS29 ?
Hallo Leute ! I'am wondering if someone have a Claisen adapter for destillation (NS29/32). In The Nederlands there is labstuff - they are on holiday for one month: that's no option. Handelskantor Freitag: out of stock. Neubert: ? Maybe there are other shops in Germany where I can buy a Claisen adapt...
- Samstag 31. Mai 2014, 18:12
- Forum: Spezielle Chemie
- Thema: Molecular orbital diagrams: some questions
- Antworten: 2
- Zugriffe: 4842
AFAIK, wouldn´t that be the basic idea: four MO´s for the double bond. Two of them with two electrons, that means four in summary and two with no electrons. Divided by two you end up with 2 for the bindungsorder...? Yes, I forgot indeed the description of the formula: b.o. = 1/2*(#e - bonding MO - ...
- Donnerstag 29. Mai 2014, 16:36
- Forum: Spezielle Chemie
- Thema: Molecular orbital diagrams: some questions
- Antworten: 2
- Zugriffe: 4842
Molecular orbital diagrams: some questions
I have to make MO diagrams but I'am not really sure if they are fully correct. Let's start with the dubble bond of trimethyl phosphinoxide. I suppose that phosphor does have sp 3 d orbitals and oxygen have sp 2 orbitals. https://illumina-chemie.org/upload/901_1080810152538745cff34e0.jpg Ok, here is ...
- Dienstag 13. Mai 2014, 18:26
- Forum: Biologie
- Thema: Genetische Manipulation von Escherichia coli
- Antworten: 43
- Zugriffe: 29931
I read the experiment and the discussions, rDNA allows us to make Green Fluorescent Proteïns (GFP) which makes (dangerous) bacteria visible with that experiment. It's also commenly used to insert a gene (or several genes) in order to make proteins for pharmaceutical purposes which are harvested in h...
- Montag 12. Mai 2014, 19:07
- Forum: Biologie
- Thema: Enzymhemmung
- Antworten: 6
- Zugriffe: 11971
It's just to say that it's not that easy - here are some calculations for the enzyme beta-galactosidase. x = K M :wink: https://illumina-chemie.org/upload/901_2198829865370ff2ecf944.jpg https://illumina-chemie.org/upload/901_1862922575370ff5080e4f.jpg https://illumina-chemie.org/upload/901_197712544...
- Montag 12. Mai 2014, 18:41
- Forum: Biologie
- Thema: Enzymhemmung
- Antworten: 6
- Zugriffe: 11971
If you discuss enzyme kinetics then you must use a organic dye to measure the amount of enzyme which is present. You have to know exactly how much inhibitor you used for further calculations. Without these data you couldn't calculate the reaction rate for catalase, turnover number, Vmax, K M , inhib...
- Freitag 18. April 2014, 22:18
- Forum: Synthesen
- Thema: Mayers Reagenz
- Antworten: 8
- Zugriffe: 15001
- Freitag 18. April 2014, 21:39
- Forum: Synthesen
- Thema: Mayers Reagenz
- Antworten: 8
- Zugriffe: 15001
This source claims the opposite:
http://wwwchem.uwimona.edu.jm/courses/C ... _Kits.html
What is your source ?
http://wwwchem.uwimona.edu.jm/courses/C ... _Kits.html
What is your source ?
- Freitag 18. April 2014, 21:07
- Forum: Synthesen
- Thema: Mayers Reagenz
- Antworten: 8
- Zugriffe: 15001
Meyer's Reagenz had a lot of problems with some special alkaloids What types of Alkaloids ? Only the adenine class of alkaloids don't give results (caffeine, theobromine and a few others), be kind these alkaloids aren't exotic. Since HgCl 2 have a pH of 3,5, the solution that is made is acid, then ...
- Freitag 18. April 2014, 18:59
- Forum: Synthesen
- Thema: Mayers Reagenz
- Antworten: 8
- Zugriffe: 15001
:D This isn't Nessler but a kind of Mayer's Reagenz. Source: Pharmacopeia http://www.pharmacopeia.cn/v29240/usp29nf24s0_ris1s126.html#usp29nf24s0_ris1s277 The difference between Nessler and Mayer's Test is that Nessler is prepared with 2 other solutions: solution 1: NaOH solution sulution 2: red mer...
- Montag 24. März 2014, 20:14
- Forum: Allgemeines zur Chemie
- Thema: [FOTOS] Kristalle, Reaktionen, Elemente etc.
- Antworten: 3350
- Zugriffe: 828927
Part 2 /3: Cu(NH 4 ) 2 (SO 4 ) 2 .6H 2 O https://illumina-chemie.org/upload/901_122704721253307b4ac1b26.jpg Kupfersulfat Pentahydrat https://illumina-chemie.org/upload/901_3699667953307b92e776b.jpg SnCl 2 .2H 2 O is more snowwhite then SrCl 2 .6H 2 O. SrI 2 is prepared to make strontium metal but it...
- Sonntag 23. März 2014, 18:56
- Forum: Allgemeines zur Chemie
- Thema: [FOTOS] Kristalle, Reaktionen, Elemente etc.
- Antworten: 3350
- Zugriffe: 828927
- Sonntag 23. März 2014, 18:20
- Forum: User-Vorstellungen
- Thema: PCl5 stellt sich vor
- Antworten: 19
- Zugriffe: 5712