Mandelin reagent problem

[Bandil]

Hi!

Swim was working on his new test reagents, when he encoutered a problem. After successfully producing large amounts of mecke, marquis etc he attempted to produce the mandeling reagent. At first, it looked fine, but after a day on the shelf it precipated as bright yellow crystals, and was almost unusable. Does anyone know what could have caused this? The reagent was stored in maybe a little bright light, but below 20 deg celc.

Swim used the following mixture of chemicals(scaled up though):
0.5 gram of ammonium vanadate in 100 milliliters of sulfuric acid...

Swim noticed that some people dilute it with 1.5 mL water, prior to the mixture with sulfuric acid... Could this be the problem?

Thanks alot!

Regards
Peter

[Rhodium]

Did a substantial amount of the solution crystallize, or was it just the ammonium vanadate you put in from the beginning (same color/amount)?

According to what I have read, 500mg ammonium vanadate is dissolved in 1.5ml H₂O and diluted to 100ml with H₂SO₄, so possibly it is the missing water, or alternatively it must be stored at room temp.




Entropy just isn't what it used to be.

[Bandil]

No. The vandate was white crystals. The amounts of crystals precipated is way more than the vandate and the color is bright yellow...

Swim will try with the water addition tonight and post his results for all of you wanna-bee safe's out there