Does gold react with sulphuric acid?

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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 »

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Offline Chemistry4me

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

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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.

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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.
If brains were made of dynamite, I wouldn't have enough to blow my nose.

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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 »

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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.
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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 »

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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.

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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)

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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 ?
Men are the same as women, just inside out !

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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...

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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.
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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

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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?

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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?

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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.

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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

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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?

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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.

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Offline Raghavendra

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

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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=  ?

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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


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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

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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 »

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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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Offline lightarrow

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Does gold react with sulphuric acid?
« Reply #25 on: 16/04/2009 13:09:43 »
Do you have to keep the temperature of the solution low?
Don't think so.

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Offline Chemistry4me

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Does gold react with sulphuric acid?
« Reply #26 on: 16/04/2009 13:19:01 »
Higher temperature favors the dinitration product when adding nitro groups onto an aromatic ring right? Or is that just my memory playing games?

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Offline lightarrow

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Does gold react with sulphuric acid?
« Reply #27 on: 16/04/2009 15:15:26 »
Higher temperature favors the dinitration product when adding nitro groups onto an aromatic ring right? Or is that just my memory playing games?
This is a different question.
Yes, higher T favors the nitrations but sometimes these reactions are auto-catalityc or the products can decompose in presence of the reagents, so you have to keep the T low enough if you don't want to go to hospital...

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Offline Chemistry4me

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Does gold react with sulphuric acid?
« Reply #28 on: 17/04/2009 02:55:17 »
Okay, got that. Thanks. [:)]

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Offline Dr.IC

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Does gold react with sulphuric acid?
« Reply #29 on: 17/04/2009 09:50:30 »
What happens when this solution is heated?
NO2+ + HSO4- + H2O

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Offline Chemistry4me

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Does gold react with sulphuric acid?
« Reply #30 on: 17/04/2009 09:56:13 »
What do you want to do?

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Offline Dr.IC

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Does gold react with sulphuric acid?
« Reply #31 on: 17/04/2009 10:41:11 »
I am mixing HNO3 and H2SO4 in the ration of 4:1, and heating it to drop on IC to make the die visible (for etching plastic).

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Offline lightarrow

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Does gold react with sulphuric acid?
« Reply #32 on: 17/04/2009 14:53:15 »
I am mixing HNO3 and H2SO4 in the ration of 4:1, and heating it to drop on IC to make the die visible (for etching plastic).
1.Why 4:1?
2.The HNO3 is more than 98%?
3.You use that mix to dissolve plastic or what, exactly?

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Offline Dr.IC

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Does gold react with sulphuric acid?
« Reply #33 on: 21/04/2009 04:38:43 »
This is to etch epoxy or plastic any of this...

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Offline Chemistry4me

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Does gold react with sulphuric acid?
« Reply #34 on: 21/04/2009 04:39:59 »
Ah, finally. The answer. And some sanity too. [:)]

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Offline Dr.IC

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Does gold react with sulphuric acid?
« Reply #35 on: 21/04/2009 04:49:41 »
I am mixing HNO3 and H2SO4 in the ration of 4:1, and heating it to drop on IC to make the die visible (for etching plastic).
1.Why 4:1?
2.The HNO3 is more than 98%?
3.You use that mix to dissolve plastic or what, exactly?

I dont know y v r using 4:1, and The HNO3 is 98%

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Offline Chemistry4me

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Does gold react with sulphuric acid?
« Reply #36 on: 21/04/2009 04:52:33 »
I dont know y v r using 4:1
Eh? Is your keyboard broken?

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Are you trying to say: I dont know why they are using 4:1?

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Offline Dr.IC

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Does gold react with sulphuric acid?
« Reply #37 on: 21/04/2009 07:38:42 »
I dont know y v r using 4:1
Eh? Is your keyboard broken?

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Are you trying to say: I dont know why they are using 4:1?
i was taking about our team. our team has been trained to use the above spec.