Sciencemadness Discussion Board

is the reaction of arsenic and iodide exothermic to a large degree, or is it more like mercury and iodine which react slowly...

quantumcorespacealchemyst - 8-4-2015 at 18:30

is the reaction of arsenic and iodide exothermic to a large degree, or is it more like the reaction of mercury and iodine (which react slowly and without much heat generation)?

i had attempted an amalgam of mercury and arsenic and found that they don't amalgate on online literature and realized there was only clumping in the flask.

after decanting the majority of the mercury to a bottle, the remaining mass of As/Hg clumps were added iodine.

so untill i find my misplaced notes there is 9.596g ?As:?Hg(ratio) and 24.711g Iodine. So possibly there will be a good data yield to calculate AsI3 to mercury iodides (Hg2I2/HgI2 ?). the arsenic iodides sublime reportedly so i hope to purify by sublimating with a cold finger and weighing the scraped precipitate(sublimate?).

Tdep - 8-4-2015 at 19:15


woelen - 8-4-2015 at 23:07

Sublimating arsenic iodide in a home/amateur setting? Are you trolling?

gardul - 9-4-2015 at 20:32

Quote: Originally posted by woelen  
Sublimating arsenic iodide in a home/amateur setting? Are you trolling?

I sure the hell hope this is a trolling thing... and if he isn'tlets hope he doesn't live in an appartment or have other living beings in his/her dwelling.

AJKOER - 14-4-2015 at 14:02

Apparently, AsI3 is a pharmaceutical preparation! Well at least once upon a time as Atomistry in its historical excerpts from the literature can be quite dated and I do recall a movie "Out of Africa" based the life of Baroness Karen Blixen, a Danish woman who emigrated to Kenya in East Africa to run a coffee plantation on the slopes of Kilimanjaro, around the outbreak of World War I in Europe, and was treated with an arsenic compound as the result of contracting a social disease. Wikipedia further comments that (see ):

"Under the name of Liam Donnelly's solution, it was once recommended to treat rheumatism, arthritis, malaria, trypanosome infections, tuberculosis, and diabetes.[2]"

Here is one cited preparation among others, which the interested reader can browse at :

"Arsenic Triiodide, AsI3, may be prepared by gently heating a mixture of the elements. The combination is accompanied by evolution of heat and, on cooling, the triiodide can be obtained by crystallisation from carbon disulphide or xylol. The elements may be heated under a reflux condenser in the presence of a solvent such as carbon disulphide, ether or chloroform, until the colour due to free iodine has disappeared (the removal of the latter is accelerated by having a small excess of arsenic present); the solution is then decanted and cooled, and the triiodide which separates is recrystallised. The product, which is a pharmaceutical preparation, should contain not less than 99 per cent. AsI3."

Apparently the reaction can be exothermic in nature and is performed in the presence of a solvent, like chloroform. Still sounds dangerous especially without a proper fume hood and equipment.

[Edited on 14-4-2015 by AJKOER]

subsecret - 15-4-2015 at 06:20

I hope you find the philosopher's stone.

quantumcorespacealchemyst - 26-7-2015 at 10:28

over days/week/or more, powders mixed in PTFE sealed jar get more clumpy. shaken a little clumps ball up, next day same, next day mostly a mass. formed to cube(ish) after transfer of a small mass from edge of the main mass, likely to have more unreacted iodine, to another like jar.

edit: the clump was formed into a cube by moving the jar around with enough force to impact deform it off the lid bottom and sides. it is part round and part flat. the separated part looks more dark purple than the larger mass which is slightly dried out looking compared to after it formed. it wasn't wet, it had a look like shinyness which is more dried and greyish dark purple. the other bit seperated is still darker purple.

[Edited on 27-7-2015 by quantumcorespacealchemyst]

quantumcorespacealchemyst - 1-4-2016 at 00:14

it kind of looks like a stone. it really solidified over time with glistening little crystal spots that were purple, and a dull dryish look to the rest, it made clinks on the glass, with not a great density, but some change in consistency from outer layer to inner. with a kind of crust like bread, maybe. it crumbled easily and ground to a powder. on re-weighing and returning to the jar, the jar was agitated and let rest, over some repetitions, the powder started to cluster up, gumming up and getting a waxy, slightly redder (all still very purple though) look to the outside, the ball lumps grew each repetition, as the first time.

when the powders were initial mixed, they were left to set for some time, before realizing the reaction was not high in energy, seemingly. over time, the mass gummed up and through slightly agitating it, it was shook better which gave better clumping and after time there was one sticky lump in the jar. impacting the jar on my hand in 6 directions gave the initial box shaped lump, with flat top and bottom, and slightly arcing 4 sides. that gummy malleable like mass, seemingly, dried out, only not in mass but in texture, as when ground recently, it crumbled much easier. the consistency changes are interesting.

now the lump has been mostly re-crushed with a stir bar and reformed to possibly gum together and be shape able better.

the teflon sheet as a primary lid, and cap buffer for an airtight fit is very useful. it doubles as a weigh plate and can be tared if removing small parts of the sticky/gummy solution (solid solution? of AsI3 with excess dissolved I2?). i am aware that adding a solvent, or rather adding too much of the material to solvent to quickly, and/or at to high a temperature, could possibly lead to a uncontrolled reaction. possibly due to sluggish reaction by mixture in solid solution. i do also want to recollect the excess iodine from the mixture.

the two pictures are after grinding and replacing in jar
and when it was reformed after pelletizing and mashing together with stir bar.
unfortunately i did not document it in the semi stone state. it has small crystals on it, most likely iodine, which were very tiny, flat and shiny and which were set on the dull crusted mass. it is quite an interesting morphing thing/system. i am interested to see if it's color dulls again.

GOPR2955.JPG - 534kBGOPR2975.JPG - 1.4MB

j_sum1 - 1-4-2016 at 00:19

Welcome back.

quantumcorespacealchemyst - 1-4-2016 at 00:33

the paste becomes more powder like, unsticky, and red when left in the mortar and pestle for a few days. it seems arsenic triiodide remains. more paste was left in the mortar and pestle from, regrinding and restoring, a smaller test chunk of the material from a different jar.

picture, before regrinding and returning to jar. (paste coating left on mortar and pestle to test color change again)

GOPR2957.JPG - 234kB

this was the test reaction, if i remember correctly, to guage the reactiveness of parts of the materials.

[Edited on 1-4-2016 by quantumcorespacealchemyst]