Sciencemadness Discussion Board

Aluminum amalgam -- is there any good reason to use it?

DrIronic101 - 24-10-2019 at 21:12

It seems like with how easily accessible hydride reducing agents (NaBH4 and LiAH4) are, there should be no reason for one to make Al/Hg for a reduction reaction. Are there any reduction reactions where Al/Hg is necessary, or can I get away with not dealing with Hg at all?

Ubya - 25-10-2019 at 02:45

surely one factor is cost. NaBH4 and LiAlH4 are expensive, if you need to reduce 10g or more of a compound, it starts getting expensive, even more if the value of the compound you are reducing is less than the hydride itself. while dealing with mercury waste is a pain in the ass, it is cheap, or at least cheaper than NaBH4 and LiAlH4

rockyit98 - 25-10-2019 at 06:01

i really don't like lead and mercury compounds specially soluble ones.in case of making Aluminum amalgam it use Hg(NO3)2 or HgCl2 as much effective than Hg metal.but for some reactions you can use GALLIUM and aluminium.like making Aluminium isopropoxide. gallium chloride can be reuse like Mercury but with much more safely.play with care, use mercury compounds as last resort. watch Nurdrage's and NileRed's videos about mercury Aluminum amalgam and mercury , gallium + Aluminum.

monolithic - 25-10-2019 at 08:45

NaBH4 and LAH are easily available only if you work in an academic or industrial facility. This is why people use Al/Hg.

karlos³ - 25-10-2019 at 11:20

I prefer to use Al/Hg for oxime reduction, as this isn't as cost or yield wise effective with a combination of borohydride with an additional reagent, for example-
Al/Hg is superior for this matter only in my opinion.

draculic acid69 - 26-10-2019 at 04:59

Quote: Originally posted by monolithic  
NaBH4 and LAH are easily available only if you work in an academic or industrial facility. This is why people use Al/Hg.


These things seem to be getting easier to acquire now than they were five or ten or 15yrs ago.

Ubya - 26-10-2019 at 05:53

Quote: Originally posted by draculic acid69  
Quote: Originally posted by monolithic  
NaBH4 and LAH are easily available only if you work in an academic or industrial facility. This is why people use Al/Hg.


These things seem to be getting easier to acquire now than they were five or ten or 15yrs ago.


but still hard and very expensive

DrIronic101 - 26-10-2019 at 21:44

Quote: Originally posted by rockyit98  
i really don't like lead and mercury compounds specially soluble ones.in case of making Aluminum amalgam it use Hg(NO3)2 or HgCl2 as much effective than Hg metal.but for some reactions you can use GALLIUM and aluminium.like making Aluminium isopropoxide. gallium chloride can be reuse like Mercury but with much more safely.play with care, use mercury compounds as last resort. watch Nurdrage's and NileRed's videos about mercury Aluminum amalgam and mercury , gallium + Aluminum.


I've heard about using Gallium as an alternative to Hg. I'm very interested in it. Is Gallium easily available?

Ubya - 27-10-2019 at 11:09

on the internet yes, it is quite easy, getting a low price for it is a bit harder. i bought mine on ebay, some bought it from galliumsource.com (now closed), there are many options while mercury is quite hard to find in reasonable quantities and prices

karlos³ - 27-10-2019 at 12:22

I have to say, I have never read, heard or seen of any success stories with gallium activated aluminium for the usual reduction methods.
I am very doubtful of its properties yet.

finding gallium

rockyit98 - 27-10-2019 at 23:08

Quote: Originally posted by DrIronic101  


I've heard about using Gallium as an alternative to Hg. I'm very interested in it. Is Gallium easily available?


mercury free thermometers have Galinstan .an alloy of Gallium, if you know some one as a vet , nurse , or doctor, thermometers get broken all the time so hospitals buy them in bulk so cheap. some times custom agents or security confiscate glass thermometers at the airport .mercury ones are very dense even if you can't tell them apart
only Galinstan will react with HCl. https://en.wikipedia.org/wiki/Galinstan

Ubya - 27-10-2019 at 23:17

i've not seen a glass termometer in a hospital in at least 10 hears, maybe where you live they still use them

rockyit98 - 27-10-2019 at 23:18

Quote: Originally posted by Ubya  
on the internet yes, it is quite easy, getting a low price for it is a bit harder. i bought mine on ebay, some bought it from galliumsource.com (now closed), there are many options while mercury is quite hard to find in reasonable quantities and prices


200$ for a kilo not that much.(The average price in for low-grade gallium was $120 per kilogram in 2016)but when you buy 50g or so it cost much more. because it need to be ship as a hazardous material for obvious reasons.

Fery - 28-10-2019 at 10:30

I've bought 1 kg of g.r. grade mercury for slightly more than 800 CZK (32 EUR) recently. If possible I would substitute it with less toxic compound in any reaction no matter of money.

rockyit98 - 28-10-2019 at 15:23

Quote: Originally posted by Ubya  
i've not seen a glass termometer in a hospital in at least 10 hears, maybe where you live they still use them

i know, but vets still use them because you can fully sterilize them with iPrOH. unlike electronic ones.i seen hospitals use temperature strips.

subsecret - 29-10-2019 at 07:06

Gallium may not be used commercially for amalgams because it's less common than mercury and a little more messy. I've experimented with it some. The chloride can be prepared by dissolving in nitric acid, precipitating the hydroxide, filtering out, and then adding HCl to make the chloride. Is there any disadvantage to just using the nitrate?

fusso - 29-10-2019 at 07:14

Because nitrate is strong oxidiser?

nleslie321 - 31-10-2019 at 05:58

NaBH4 is so easy to get and cheap i pay like $18 for 100g i dont bother with the huge toxic mess of Al/Hg amalgam.

monolithic - 31-10-2019 at 08:19

Quote: Originally posted by nleslie321  
NaBH4 is so easy to get and cheap i pay like $18 for 100g i dont bother with the huge toxic mess of Al/Hg amalgam.


What country? It's way more than that in the USA.

DrIronic101 - 7-11-2019 at 19:42

Quote: Originally posted by nleslie321  
NaBH4 is so easy to get and cheap i pay like $18 for 100g i dont bother with the huge toxic mess of Al/Hg amalgam.

Where the hell do you live that NaBH4 costs that little? Here in the US it's not only nearly impossible to find for sale to the average individual, but it's tremendously expensive.