The Vespiary

The Hive => Chemicals & Equipment => Topic started by: rookee on April 23, 2002, 09:20:00 AM

Title: how to make sodium dichromate?
Post by: rookee on April 23, 2002, 09:20:00 AM
SWIM has access to lots of unwatched/uncontrolled substances but fucking no way to get this sodium dichromate.
is there any way to synthesise it easily???

greets
rookee
Title: potassium dichromate
Post by: Rhodium on April 23, 2002, 12:01:00 PM

https://www.thevespiary.org/rhodium/Rhodium/chemistry/potassium.dichromate.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/potassium.dichromate.html)

Title: so i just have to exchange potassium with sodium?
Post by: rookee on April 23, 2002, 09:22:00 PM
so i just have to exchange potassium with sodium?
i.e. NaOH instead of KOH???  :P
thanks
Title: Don't make it, buy it.
Post by: psychokitty on April 23, 2002, 10:02:00 PM
Don't make it, buy it.

Potassium dichromate is available from companies that distribute photographic chemicals.  Cheap too.

Title: Agreed
Post by: Chromic on April 24, 2002, 12:46:00 AM
Don't bother making your reagents... purchase them! There's nothing suspicious about purchasing a small to medium amount of dichromate.
Title: Also available...
Post by: Elementary on April 24, 2002, 01:45:00 AM
From wood finishing/french polishing suppliers. Used as a water based stain, called Bichromate of Potash.

Nobodys home
Title: use potassium-Cr2 instead of sodium-Cr2???
Post by: rookee on April 24, 2002, 10:50:00 AM
but can SWIM use potassium dichromat in the synthesis of copper(II)chromite instead of sodium dichromat?  8)
Title: aquisition of dichromate
Post by: MTM on April 24, 2002, 12:51:00 PM
>Don't bother making your reagents... purchase them!
In some countries dichromate is watched because it´s toxic. That´s why you need a permission to buy it. I guess rookee lives in such a country and I fear that´s why he/she is definitely not able to get it in a store.

M T M
Title: Did you read anything about this?
Post by: Belial on April 24, 2002, 01:15:00 PM
Rookee Did you read anything about this?
perhaps 248449 where placebo states:

"BTW, SWIM used Copper Nitrate and sodium chromate for the catalyst, and due to lack of supply, SWIM also tried Pottasium chromate with positive results."
Title: SWIM is from germany, where nearly everything is ...
Post by: rookee on April 24, 2002, 09:25:00 PM
SWIM is from germany, where nearly everything is watched and controlled...  >:(
so he has to synthesise almost anything.
rookee
Title: Germany?
Post by: psychokitty on April 25, 2002, 06:36:00 AM
How the hell do you guys learn to speak english?  Is that a required course over there?  (BTW, that is good, not bad).
Title: English
Post by: hest on April 25, 2002, 11:47:00 AM
Yes it is.
Most lit. are written in English or German. I'm from a country where we are only a few mill. people. Gues how much advanced chem. lit there is written on my birth language (and that's why the spelling somtimes is a bit 'strange' )
;D
Title: yeah, here you have to learn english in ...
Post by: rookee on April 25, 2002, 10:52:00 PM
yeah, here you have to learn english in elementary school, when your are 10 or 11 years old.
english is not that hard to learn! but french is a big bite in the ass!  :-[
Title: english vs french
Post by: MTM on April 26, 2002, 03:42:00 PM
>english is not that hard to learn! but french is a big bite in the ass!

how true!

M T M
Title: word
Post by: Richy on April 18, 2003, 09:09:00 AM
yes, agreed there. my french teacher may have as well said that line from the alien on the simpsons> "in order for you to pronounce it correctly, i would have to, erm, rip out your tongue"

Title: Dye mordant
Post by: ylid on April 18, 2003, 08:21:00 PM
Potassium chromate is available in some countries from specialist art and craft suppliers as a dye mordant.

Title: acetaldehyde
Post by: Richy on April 21, 2003, 10:15:00 AM
for the acetaldehyde synth can this potassium dichromate substitute the sodium

Title: K2Cr207 substitution
Post by: ylid on April 21, 2003, 11:50:00 AM
The dichromate ion is the bit that does the oxidising, so I think the only chemical difference between the Na+ and K+ salts is their solubility. K2Cr2O7 is less soluble, especially in cold water. Na2Cr2O7 is hydroscopic, so it's hard to weigh out exact amounts. For this reason K2Cr2O7 is preferred for volumetric analysis.