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Author Topic: Does gold react with sulphuric acid?  (Read 25134 times)

Offline Dr.IC

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Does gold react with sulphuric acid?
« on: 11/03/2009 08:49:22 »
Does Sulphuric acid reacts with gold wire.
« Last Edit: 06/04/2009 23:33:18 by chris »


 

Offline Chemistry4me

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Re: Does gold react with sulphuric acid?
« Reply #1 on: 11/03/2009 09:14:22 »
No.
 

Offline Dr.IC

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Re: Does gold react with sulphuric acid?
« Reply #2 on: 11/03/2009 09:34:55 »
Which acid is preferable for the reaction, i want to see corrosion on the wire.
 

Offline Don_1

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Re: Does gold react with sulphuric acid?
« Reply #3 on: 11/03/2009 09:44:51 »
So far as I'm aware, no acid or alkali reacts with pure gold. I could be wrong though. If it does, then the gold was not pure and the reaction is with the impurities rather than the gold.
 

Offline lightarrow

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Re: Does gold react with sulphuric acid?
« Reply #4 on: 11/03/2009 13:19:24 »
Which acid is preferable for the reaction, i want to see corrosion on the wire.
Aqua regia:
http://en.wikipedia.org/wiki/Aqua_regia

Another way: cianide (ex. KCN) in presence of air oxygen, or another oxidant, ex. H2O2; in this second way (the reaction is called "bombing" in gold laboratories/firms) you MUST use a totally closed hood with tubes to put hands, because CN- can also be oxidized to (CN)2 which can kill you in a few seconds.

Instead of Aqua_regia you can also use HCl + H2O2 (it makes Cl2) but it's slightly less effective. In both cases you have to heat up a little.
« Last Edit: 11/03/2009 13:26:45 by lightarrow »
 

Offline Bored chemist

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Re: Does gold react with sulphuric acid?
« Reply #5 on: 11/03/2009 18:23:28 »
I have read, but never bothered to verify, that telluric acid dissolves gold.
However, if I wanted to dissolve gold I would use HCl/HNO3.
 

Offline lightarrow

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Re: Does gold react with sulphuric acid?
« Reply #6 on: 11/03/2009 22:50:23 »
I have read, but never bothered to verify, that telluric acid dissolves gold.
However, if I wanted to dissolve gold I would use HCl/HNO3.
It should be Selenic acid:
http://pubs.acs.org/doi/abs/10.1021/ja01995a007
http://en.wikipedia.org/wiki/Selenic_acid
« Last Edit: 11/03/2009 22:54:01 by lightarrow »
 

Offline Dr.IC

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Re: Does gold react with sulphuric acid?
« Reply #7 on: 03/04/2009 08:16:11 »
How about nitric acid? does this work.
 

Offline lightarrow

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Re: Does gold react with sulphuric acid?
« Reply #8 on: 03/04/2009 13:54:59 »
How about nitric acid? does this work.
No, you need a complexant together with the oxidant (es. Cl- ions)
 

Offline neilep

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Re: Does gold react with sulphuric acid?
« Reply #9 on: 03/04/2009 15:37:16 »
We make rings out of gold ewe know !

ewe can buy one off me and then conduct your tests ?..

..see how I try to help ?
 

Offline Dr.IC

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Does gold react with sulphuric acid?
« Reply #10 on: 07/04/2009 04:52:52 »
I have enough of gold wire to conduct tests....... if i am in short i will send u a message...
 

Offline Bored chemist

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Does gold react with sulphuric acid?
« Reply #11 on: 07/04/2009 20:45:16 »
I have read, but never bothered to verify, that telluric acid dissolves gold.
However, if I wanted to dissolve gold I would use HCl/HNO3.
It should be Selenic acid:
http://pubs.acs.org/doi/abs/10.1021/ja01995a007
http://en.wikipedia.org/wiki/Selenic_acid
OOps, sorry, wrong group VI element.
 

Offline Raghavendra

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Does gold react with sulphuric acid?
« Reply #12 on: 09/04/2009 09:19:13 »
No,, But can't say ... under drastic condition it can change
 

Offline lightarrow

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Does gold react with sulphuric acid?
« Reply #13 on: 09/04/2009 13:30:59 »
No,, But can't say ... under drastic condition it can change
what can change?
 

Offline Chemistry4me

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Does gold react with sulphuric acid?
« Reply #14 on: 09/04/2009 14:07:38 »
The fact that gold does react with sulphuric acid under drastic conditions?
 

Offline lightarrow

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Does gold react with sulphuric acid?
« Reply #15 on: 09/04/2009 21:22:43 »
The fact that gold does react with sulphuric acid under drastic conditions?
Ah, I believed he answered BC... :)
No, sulphuric acid cannot react with gold, even under drastic conditions; the acid is not complexant.
 

Offline Raghavendra

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Does gold react with sulphuric acid?
« Reply #16 on: 10/04/2009 08:24:23 »
 Ohh u mean gold doesn't react with sulfuric acid...

 It's not true...

But it reacts on some how.

The reaction of sub-ppm amounts of SO2 and NO2 in dry and humid air on a gold foil was studied using a chemical reactor technique. Initially a humidity-independent transient reaction occurs that produces NO and SO3. This reaction is inhibited by the sulfuric acid formed. After this stage another reaction follows that is strongly humidity-dependent and occurs on the gold surface beneath a film of aqueous sulfuric acid. This reaction produces HNO2, NO, and H2SO4
 

Offline lightarrow

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Does gold react with sulphuric acid?
« Reply #17 on: 10/04/2009 16:52:45 »
Ohh u mean gold doesn't react with sulfuric acid...

 It's not true...

But it reacts on some how.

The reaction of sub-ppm amounts of SO2 and NO2 in dry and humid air on a gold foil was studied using a chemical reactor technique. Initially a humidity-independent transient reaction occurs that produces NO and SO3. This reaction is inhibited by the sulfuric acid formed. After this stage another reaction follows that is strongly humidity-dependent and occurs on the gold surface beneath a film of aqueous sulfuric acid. This reaction produces HNO2, NO, and H2SO4
What does <<SO2 and NO2 in dry and humid air>> have to do with sulphuric acid?
 

Offline Chemistry4me

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Does gold react with sulphuric acid?
« Reply #18 on: 11/04/2009 04:06:16 »
If anything:

This reaction is inhibited by the sulfuric acid formed.
 

Offline Raghavendra

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Does gold react with sulphuric acid?
« Reply #19 on: 12/04/2009 08:34:52 »
ya [8D]
 

Offline Dr.IC

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Does gold react with sulphuric acid?
« Reply #20 on: 16/04/2009 05:44:12 »
what is the product of
H2SO4+HNO3=  ?
 

Offline Chemistry4me

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Does gold react with sulphuric acid?
« Reply #21 on: 16/04/2009 05:53:25 »
Ooo! I was just doing that yesterday! :)

HNO3 + H2SO4 ↔ NO2+ + HSO4- + H2O

 

Offline Raghavendra

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Does gold react with sulphuric acid?
« Reply #22 on: 16/04/2009 06:17:56 »
It's a simple answer any one would have answered it....


 Answer is H2O+NO2+(-)HSO4
 

Offline lightarrow

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Does gold react with sulphuric acid?
« Reply #23 on: 16/04/2009 13:02:18 »
Yes, however the acids must be quite pure (almost no water) and H2SO4 must be in excess (to bind the water molecule formed in the reaction) or the very strong acid NO2+ will react again with water:

NO2+ + H2O --> HNO3 + H+.
« Last Edit: 16/04/2009 13:05:39 by lightarrow »
 

Offline Chemistry4me

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Does gold react with sulphuric acid?
« Reply #24 on: 16/04/2009 13:08:45 »
Do you have to keep the temperature of the solution low?
 

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Does gold react with sulphuric acid?
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