Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Aluminium amalgam
Hboomans
Harmless
*




Posts: 6
Registered: 17-2-2014
Location: Netherlands
Member Is Offline

Mood: No Mood

[*] posted on 30-4-2014 at 10:32
Aluminium amalgam


Can someone help me with a good preparation of an aluminium amalgam because i'm sure i'm doing something wrong.

I was making an aluminium amalgam by a 2% solution of Mercury(ii)Nitrate in 200ml distilled water
I've cut 50gr aluminium foil in squares 2x2cm and put them in a beaker. Then i've put the solution over the aluminium and let it sit for a couple minutes till hydrogen gas is vissible.

After a few minutes I've discarded the mercury solution and washed the alu foil with water. But when the water came in contact with the alu foil the reaction started and almost all alu foil disolved.

What have I done wrong??

[Edited on 30-4-2014 by Hboomans]
View user's profile View All Posts By User
leu
National Hazard
****




Posts: 368
Registered: 13-10-2005
Member Is Offline

Mood: No Mood

[*] posted on 30-4-2014 at 11:10


Mercuric Nitrate is less soluble so it takes longer to get an amalgamation going than with mercuric chloride ;) The mercuric ion can serve as a catalyst turning aluminum foil into aluminum hydroxide which produces hydrogen gas during the reaction :P Mercuric Iodide is more soluble than mercuric nitrate and thus might be more suited to your needs :cool:



Chemistry is our Covalent Bond
View user's profile View All Posts By User
macckone
International Hazard
*****




Posts: 1393
Registered: 1-3-2013
Location: Over a mile high
Member Is Offline

Mood: Electrical

[*] posted on 30-4-2014 at 18:36


Try using a more dilute solution of nitrate or a thicker grade of
aluminum foil with a larger quantity of foil.

It sounds like you are forming amalgam it is just too reactive.
View user's profile View All Posts By User
GoldGuy
Harmless
*




Posts: 45
Registered: 24-11-2013
Location: Toronto, ON
Member Is Offline

Mood: Not sure if awake or in a dream where Im trying to fully awake.

[*] posted on 30-4-2014 at 19:58


You are using 5-10 times the amount of mercury necessary
View user's profile View All Posts By User
CycloKnight
Hazard to Others
***




Posts: 127
Registered: 4-8-2003
Member Is Offline

Mood: Still waiting for the emulsion to settle.

[*] posted on 30-4-2014 at 23:41


I've always had better success with sliced up aluminium pie tins. When thin aluminium foil has been consumed the surface area becomes very high and the reaction can be very uncontrollable (depending on application). Thicker Al is also a lot less work to slice up (per gram) with some heavy duty scissors.
View user's profile View All Posts By User
Hboomans
Harmless
*




Posts: 6
Registered: 17-2-2014
Location: Netherlands
Member Is Offline

Mood: No Mood

[*] posted on 3-5-2014 at 03:16


I've done the amalgamation this time with the information you all gave me.

I've cut 30gr aluminium foil in sqaures about 2.5cm x 2.5cm and put them in a coffee grinder for a few seconds (because i've read this on the internet about the coffee grinder)
I've placed the aluminium foil in a beaker and put 500ml h2o over the foil. The h2o i've made this first in a plastic bottle with 400mg mercury nitrate, after about 10mins I saw that amalgamation has started so after that i've let it amalgamate for approx. another 10min.
After the amalgamation I discarded the h2o.
Now i've put the aluminium in my reaction vessel but nownothing happend, waited for 15min. still nothing happens. So I considerd putting another 400mg mercury in the reaction vessel, after 2min. the reaction became so violent that it blows out of the condensor.

The foil I used i've measured it and it was .02mm so I've fold it once to get .04mm

What could have gone wrong??


I'm thinking of using aluminium barbeque trays the are .12mm thick. The reaction would be less violent, but the reaction would take longer. But does anyone now how much longer the reaction will take place? Is there a way I can calculate that?
View user's profile View All Posts By User
Nicodem
Super Moderator
Thread Moved
3-5-2014 at 09:10
zed
International Hazard
*****




Posts: 1766
Registered: 6-9-2008
Location: Great State of Jefferson, City of Portland
Member Is Offline

Mood: Semi-repentant Sith Lord

[*] posted on 3-5-2014 at 12:05


Umm. I had a buddy that used to run reductions with Aluminum Amalgam. Utilized a bathtub full of ice, and small, portion-wise additions of ingredients to control the vigor of reaction.

That blowing out the condensor event....it isn't good. Commonly vents lots of hydrogen into the room, where it may mix with air and detonate. Not healthy for living things.
View user's profile View All Posts By User
leu
National Hazard
****




Posts: 368
Registered: 13-10-2005
Member Is Offline

Mood: No Mood

[*] posted on 4-5-2014 at 10:49


The time taken for the reaction to run to completion depends on what substrate is being reduced :P The fact that the contents of the reaction vessel were ejected through the condenser says that the substrate that you posted questions about in another thread recently results in a rather exothermic reaction which is what caused the new decorative markings on the ceiling :o Your equipment isn't adequate for what you're trying to do in it, so maybe you should study the subject more thoroughly before making another attempt at redecorating :) There's plenty of information about your queries available online already so there was really no need for this thread to be posted :cool:



Chemistry is our Covalent Bond
View user's profile View All Posts By User

  Go To Top