| Pages:
1
2 |
12AX7
Post Harlot
Posts: 4803
Registered: 8-3-2005
Location: oscillating
Member Is Offline
Mood: informative
|
|
Wouldn't that just form Mg(OH)2?
FWIW, Mg in small amounts (up to maybe 5%) is in solid solution with the alpha aluminum.
Tim
|
|
|
MostlyAir
Harmless
Posts: 1
Registered: 16-12-2011
Location: Crested Butte
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Tacho  | 1- a spatula tip of Hg2Cl2 (calomel) in a test tube.
2- add 1ml HCl 37%
3- add 1ml H2O2 as concentrated as you can get. I used 30%, but I gess 10% would work
4- Put a cottom plug on top of the tube -heat on a small flame, don't boil it - a vigorous reaction (bubbling) takes place - be carefull with the
spray (mist) comming from it, it has very poisonous mercuric chloride in it, hence the cottom plug.
5- the crystal clear solution left (no calomel precipitate) is a mecuric chloride solution. Insert a piece of clean copper wire in the solution(thanks
Polverone). It should come out silvery because it's coated with Hg.
6- Use "as is" diluted in water or neutralize first and get rid of the excess H2O2 with manganese dioxide. I use my marvelous catalyst to do it. Don't forget the cottom plug here. |
I cam across this website yesterday while searching for a way to turn about a gram or so of the Hg2Cl2 I had into at least a half a gram of HgCl2 (the
way more soluble mercury salt I could use). I know this is a very old post, but I am presently attempting this reaction (http://www.sciencemadness.org/talk/viewthread.php?tid=4248&a...), with slight modifications (because I don't have the chemicals is their
concentration, as suggested), and am hoping for some feedback.
Here's what I did:
In a test tube, I placed 800mg of Hg2Cl2, 1mL of HCL (only 29%) and 8mL of H202 (3% from a drug store), then capped it off with a cotton ball as
advised. I increased the H202 amount because I figured it would be necessary to offset the low concentration of the solution. Then I placed the test
tube in a water bath on my hot plate stirrer and heated it up to about 85C.
The white Hg2Cl2 powder is at the bottom of the tube, and lots of tiny, very small bubbles are rising out of it (I'm hoping as a result of the
reaction, and not merely the heat from the water bath). That said, these bubbles are hardly "vigorous" and it has been an hour so far and it hardly
seems like any of the calomel has reacted or reduced.
Is the procedure doomed because of the lower concentrations of HCL & Hydrogen Peroxide? Or do I just need to be patient? Should I adjust the
amounts of the reagents? Or should I just wait until next week when I can try to acquire some real Hydrogen Peroxide (which I really would rather not
do because it's such a pain to order and pickup). Thanks for all your help!
EDIT/UPDATE:
I was patient, and waited over 6 hours for this to process. During this time, I added another 1mL of HCL (29%) and another 12 mL of H2O2 (3%) in 3
different additions of 4 mL as the reaction bubbling slowed.
After 6 hours, the Hg2Cl2 didn't fully disolve but the H2O2 bubbles were gone again and I was tired of waiting...and I only needed about 400-500mg of
HgCl2 for my reaction anyway, so I decided to use the tube's contents (now about 20mL of mostly acidic water and a little of the original Hg2Cl2 on
the bottom).
The Al amalgam was a success within 5 minutes of me adding the tube's contents down the condenser. Too much of a success actually (I got a manageable,
but frightening reflux up the condensor in about 10 minutes). Ultimately though, my patience paid off and I was able to achieve my goals with only the
chemicals on hand. Just thought I'd share it with you in case 3% Hydrogen Peroxide is all you have at the moment...
[Edited on 17-12-2011 by MostlyAir]
|
|
|
| Pages:
1
2 |
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
