khourygeo78
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A newbie questions
Hello,
i'd like to know 2 things about chemistry
-1- If I melt or heat a metal or mineral a little below melting point or until it gets red hot, will it oxidize?
-2- Is it possible to store a very volatile liquid (boiling point: ~10 degrees C) without risking an explosion, and with common materials available
everywhere?
Thanks
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Volanschemia
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Both of your questions depend greatly on the compound in question.
When something gets "red hot", it is simply black body radiation given off from the system, it has nothing to do with melting point.
There are also various ways a compound can decompose or react away, oxidizing being one of them.
Some compounds will decompose well above their melting point, some on their melting point and some below. It all depends on what you are heating.
Volatility is not the only factor to consider when storing a compound. Vapour pressure is also a big contributor. Both characteristics vary with
different compounds.
Look up the terms "volatility" and "vapour pressure" if you want to know more.
"The chemists are a strange class of mortals, impelled by an almost insane impulse to seek their pleasures amid smoke and
vapor, soot and flame, poisons and poverty; yet among all these evils I seem to live so sweetly that may I die if I were to change places with the
Persian king" - Johann Joachim Becher, 1635 to 1682.
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Sulaiman
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A metal or mineral below its melting point is a solid, so any effects will be superficial.
Most metals that I can think of usually form an oxide layer at room temperature when exposed to the atmosphere,
gold, platinum etc. I think do not form an oxide layer.
if you heat the object what happens depends upon the surrounding atmosphere,
e.g. the inner blue part of a flame may reduce the oxide layer to the metal, the outer part will almost certainly increase oxide layer thickness.
In general, heating in air will increase oxide layer thickness.
the pressure of gas above a liquid is its vapour pressure,
which is a function of temperature, liquids boil when vapour pressure >= actual pressure.
Pressure vs. temperature graphs have been made for most chemicals and are fairly easy to find via google.
A couple of common chemicals that are prevented from boiling at temperatures above their atmospheric pressure boiling point
are liquid butane (b.p. c0C) and propane (b.p. -42C)
If you look for pressure vs temperature (phase) diagrams for your chemical
you can determine what pressure is required for the chemical to remain liquid at a given temperature.
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ave369
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A BP of 10 degrees Celsius is already gas territory. It's not a liquid at STP, and at 10 degrees it's a liquified gas. You can store it in a
pressurizable tank.
Smells like ammonia....
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crystal grower
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I agree with Volanschemia, and by the way as your subject says this thread belongs to begginings  .
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Volanschemia
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Quote: Originally posted by Sulaiman  | A metal or mineral below its melting point is a solid, so any effects will be superficial.
Most metals that I can think of usually form an oxide layer at room temperature when exposed to the atmosphere,
gold, platinum etc. I think do not form an oxide layer.
if you heat the object what happens depends upon the surrounding atmosphere,
e.g. the inner blue part of a flame may reduce the oxide layer to the metal, the outer part will almost certainly increase oxide layer thickness.
In general, heating in air will increase oxide layer thickness.
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The above doesn't apply to everything. Most metals will form an oxide layer, but compound are subject to different rules (from minerals, I'm
gathering the OP meant compounds in general).
In addition to this, there are many compounds that are solid at STP that decompose well below any melting point.
| Quote: | | I agree with Volanschemia, and by the way as your subject says this thread belongs to begginings . |
I'm sure a mod will move it in the near future
"The chemists are a strange class of mortals, impelled by an almost insane impulse to seek their pleasures amid smoke and
vapor, soot and flame, poisons and poverty; yet among all these evils I seem to live so sweetly that may I die if I were to change places with the
Persian king" - Johann Joachim Becher, 1635 to 1682.
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khourygeo78
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| Quote: Originally posted by Volanschemia | Both of your questions depend greatly on the compound in question.
When something gets "red hot", it is simply black body radiation given off from the system, it has nothing to do with melting point.
There are also various ways a compound can decompose or react away, oxidizing being one of them.
Some compounds will decompose well above their melting point, some on their melting point and some below. It all depends on what you are heating.
Volatility is not the only factor to consider when storing a compound. Vapour pressure is also a big contributor. Both characteristics vary with
different compounds.
Look up the terms "volatility" and "vapour pressure" if you want to know more. |
If one is heating lead, tin, bismuth, arsenic or antimony in their common forms for example? Is there a page that can possibly explain which
minerals/metals will be altered and at which temperatures etc?
Thanks for the info
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Volanschemia
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Melting points for elements can be found on a lot of Periodic Tables.
Most metals will form an oxide layer with time, some faster, others slower. All the metals you mentioned can be melted and cast into an ingot without
major loss due to oxidation (except Arsenic, which I am unsure about).
If you want to avoid oxidation when melting a metal, heating in a crucible with a lid would be a good way to go.
"The chemists are a strange class of mortals, impelled by an almost insane impulse to seek their pleasures amid smoke and
vapor, soot and flame, poisons and poverty; yet among all these evils I seem to live so sweetly that may I die if I were to change places with the
Persian king" - Johann Joachim Becher, 1635 to 1682.
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khourygeo78
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| Quote: Originally posted by Sulaiman | A metal or mineral below its melting point is a solid, so any effects will be superficial.
Most metals that I can think of usually form an oxide layer at room temperature when exposed to the atmosphere,
gold, platinum etc. I think do not form an oxide layer.
if you heat the object what happens depends upon the surrounding atmosphere,
e.g. the inner blue part of a flame may reduce the oxide layer to the metal, the outer part will almost certainly increase oxide layer thickness.
In general, heating in air will increase oxide layer thickness.
the pressure of gas above a liquid is its vapour pressure,
which is a function of temperature, liquids boil when vapour pressure >= actual pressure.
Pressure vs. temperature graphs have been made for most chemicals and are fairly easy to find via google.
A couple of common chemicals that are prevented from boiling at temperatures above their atmospheric pressure boiling point
are liquid butane (b.p. c0C) and propane (b.p. -42C)
If you look for pressure vs temperature (phase) diagrams for your chemical
you can determine what pressure is required for the chemical to remain liquid at a given temperature.
|
But isnt there a way to turn some metals like that of lead or tin which easily tarnish into oxides completely by subjecting them to fire?
Will look at the pressure thing. Will have much to read it seems.
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khourygeo78
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| Quote: Originally posted by Volanschemia | Melting points for elements can be found on a lot of Periodic Tables.
Most metals will form an oxide layer with time, some faster, others slower. All the metals you mentioned can be melted and cast into an ingot without
major loss due to oxidation (except Arsenic, which I am unsure about).
If you want to avoid oxidation when melting a metal, heating in a crucible with a lid would be a good way to go. |
I actually want to oxidize metals/minerals in the biggest quantity in a fast way. I thought heating to a certain degree on each of these not so stable
minerals may possibly do it in a few hours
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crystal grower
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| Quote: Originally posted by khourygeo78 |
I actually want to oxidize metals/minerals in the biggest quantity in a fast way. I thought heating to a certain degree on each of these not so stable
minerals may possibly do it in a few hours |
Crush them to dust and heat it with gas torch.
[Edited on 26-3-2016 by crystal grower]
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Tsjerk
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Do you have access to hydrochloric acid (HCl) and nitric acid? A mixture of those will do exactly what you want.
HCl and any soluble nitrate salt will also suffice. HCl is available as rust remover at DIY stores.
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khourygeo78
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| Quote: Originally posted by crystal grower | | Quote: Originally posted by khourygeo78 |
I actually want to oxidize metals/minerals in the biggest quantity in a fast way. I thought heating to a certain degree on each of these not so stable
minerals may possibly do it in a few hours |
Crush them to dust and heat it with gas torch.
[Edited on 26-3-2016 by crystal grower] |
How can I crush them into dust with no machine?
However, I think if they will be melted it would be pointless to crush them,no?
I just want to make sure if heating with a gas torch will oxidize them completely or partially or little bit
| Quote: Originally posted by Tsjerk | Do you have access to hydrochloric acid (HCl) and nitric acid? A mixture of those will do exactly what you want.
HCl and any soluble nitrate salt will also suffice. HCl is available as rust remover at DIY stores. |
Unfortunately, I only have access to acetic acid.
I can make hcl but in small quantities, but it is most likely that hcl will be needed in big quantity&concentration to oxidize a big quantity of
minerals/metals, no? HCL would not oxidize bigger quantity of minerals, no?
I will try to see if diy stores have hcl. Diy stores are very small here, I'm living in a 3rd world country, and am finding it difficult to even find
common acetic acid. And nitrates arent available also, unfortunately
[Edited on 26-3-2016 by khourygeo78]
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karlos³
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| Quote: | How can I crush them into dust with no machine?
However, I think if they will be melted it would be pointless to crush them,no? |
If the material is crushed before it will be melted, it will melt much faster because of the greater surface area.
If the material to be crushed in question is a metal, be careful as many metals in powdered form can be ignited and burn then violent as well.
Better check if a metal to be crushed melted is one of those.
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Texium
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Thread Moved
26-3-2016 at 06:05 |
aga
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| Quote: Originally posted by Sulaiman | A couple of common chemicals that are prevented from boiling at temperatures above their atmospheric pressure boiling point
are liquid butane (b.p. c0C) and propane (b.p. -42C) |
Interesting !
Is there an explanation why that would be ?
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crystal grower
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| Quote: Originally posted by karlos³ | | Quote: | How can I crush them into dust with no machine?
However, I think if they will be melted it would be pointless to crush them,no? |
If the material is crushed before it will be melted, it will melt much faster because of the greater surface area.
If the material to be crushed in question is a metal, be careful as many metals in powdered form can be ignited and burn then violent as well.
Better check if a metal to be crushed melted is one of those. |
Im not sure what did you want to say, I meant that powdered material oxidize a lot faster before it is molten.
@ khourygeo78 Please be more specific. exactly what material are u going to oxidize? We can't help you if we don't know whether you want to oxide
ingot of tin or diamond block.
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crystal grower
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| Quote: Originally posted by karlos³ | | Quote: | How can I crush them into dust with no machine?
However, I think if they will be melted it would be pointless to crush them,no? |
If the material is crushed before it will be melted, it will melt much faster because of the greater surface area.
If the material to be crushed in question is a metal, be careful as many metals in powdered form can be ignited and burn then violent as well.
Better check if a metal to be crushed melted is one of those. |
Im not sure what did you want to say, I meant that powdered material oxidize a lot faster before it is molten.
@ khourygeo78 Please be more specific. exactly what material are u going to oxidize? We can't help you if we don't know whether you want to oxide
ingot of tin or diamond block.
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khourygeo78
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| Quote: Originally posted by crystal grower | | Quote: Originally posted by karlos³ | | Quote: | How can I crush them into dust with no machine?
However, I think if they will be melted it would be pointless to crush them,no? |
If the material is crushed before it will be melted, it will melt much faster because of the greater surface area.
If the material to be crushed in question is a metal, be careful as many metals in powdered form can be ignited and burn then violent as well.
Better check if a metal to be crushed melted is one of those. |
Im not sure what did you want to say, I meant that powdered material oxidize a lot faster before it is molten.
@ khourygeo78 Please be more specific. exactly what material are u going to oxidize? We can't help you if we don't know whether you want to oxide
ingot of tin or diamond block.
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Hello crystal,
Bismuth, Tin, lead, tin-lead alloy, arsenic, antimony
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crystal grower
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[rquote]
Hello crystal,
Bismuth, Tin, lead, tin-lead alloys, arsenic, antimony[/rquote]
I can't help you with arsenic as I haven't worked with it yet.
It's a pity you don't even have hcl.
For bismuth, tin and lead this could work:
Melt the metal and pour it from height to water. You should get metal in form of smaplbl droplets. Then heat this metal to the temperature near the
m.p. but do not melt it. It should oxidize quite quicky.
NOTE: I haven't try this yet its just my advice, and be careful if you want to try it could be quite dangerous.
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khourygeo78
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| Quote: Originally posted by crystal grower |
[rquote]
Hello crystal,
Bismuth, Tin, lead, tin-lead alloys, arsenic, antimony[/rquote]
I can't help you with arsenic as I haven't worked with it yet.
It's a pity you don't even have hcl.
For bismuth, tin and lead this could work:
Melt the metal and pour it from height to water. You should get metal in form of smaplbl droplets. Then heat this metal to the temperature near the
m.p. but do not melt it. It should oxidize quite quicky.
NOTE: I haven't try this yet its just my advice, and be careful if you want to try it could be quite dangerous. |
Ok, thanks for your advice.
Why is it dangerous?
Let's say I get 1L of HCL (without including water added), how much of metal can it oxidize pretty much?
If it proves effective, I can organize a way to make big quantities, but I'm afraid of corrosive substances and of possible dangerous chlorides I may
have to work out with
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crystal grower
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Simply said, hot metal and water isn't a good combination .
The reaction of tin with hcl is:
2HCl + Sn ----> SnCl2 + H2
With 1000g of pure hcl you can oxidize 1627.90g of tin , you must calculate it with concentration of hcl you have.
But this won't work with lead, bismuth and probably with antimony neither.
For these you probably need HNO3 at least.
[Edited on 27-3-2016 by crystal grower]
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khourygeo78
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| Quote: Originally posted by crystal grower | Simply said, hot metal and water isn't a good combination .
The reaction of tin with hcl is:
2HCl + Sn ----> SnCl2 + H2
With 1000g of pure hcl you can oxidize 1627.90g of tin , you must calculate it with concentration of hcl you have.
But this won't work with lead, bismuth and probably with antimony neither.
For these you probably need HNO3 at least.
[Edited on 27-3-2016 by crystal grower] |
Thanks for your help. I have checked about adding molten metal to water on youtube videos, it seemed not dangerous unless you burn yourself by
touching the molten metal or near it.
Last question: I can get my hand on big quantities of sulfur from agriculture store. I was thinking about melting a metal with sulfur, and therefore I
get metal sulfide. Then I react with acetic acid concentration 10%, I'll get acetate and hydrogen sulfide which is very toxic. If I do this reaction
outdoors, it wont matter, right? Because 10% acetic acid will react very slowly with the sulfide (?)
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crystal grower
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Hmmmm.....
Firstly you should probably use metal in powdered or at least granuled form because if you will mix large pieces of metal with sulfur and heat it, the
majority of sulfur won't react with metal but will simply burn to SO2.
Secondly I'm not sure if these metal sulfides will even react with acetic acid in this concentration or in acetic acid generally (maybe im wrong).
Hydrogen sulfide is a pretty nasty stuff maybe u could somehow oxidize it with
H2O2 to S or H2SO4.
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khourygeo78
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| Quote: Originally posted by crystal grower | Hmmmm.....
Firstly you should probably use metal in powdered or at least granuled form because if you will mix large pieces of metal with sulfur and heat it, the
majority of sulfur won't react with metal but will simply burn to SO2.
Secondly I'm not sure if these metal sulfides will even react with acetic acid in this concentration or in acetic acid generally (maybe im wrong).
Hydrogen sulfide is a pretty nasty stuff maybe u could somehow oxidize it with
H2O2 to S or H2SO4. |
The metals I'm using melt easily at low heat, so I can melt sulfur with them at the same temperature and it wont matter as they will both be in liquid
state (on bismuth-lead/tin). Wont be working with antimony or arsenic because they are much more toxic, just wanted to get info about them
I googled the reaction and saw that sulfides react with acetic acid to give h2s and acetates. But I think it will be a slow reaction especially that
the acetic acid is diluted. I was thinking about reacting maybe like 5g later on. I think such a small quantity reacting slowly will be harmless.
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Sulaiman
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khourygeo78
good to see the research, H2S is indeed very toxic
it is also incredibly smelly, stink-bomb gas, it can stink up a surprisingly large area 
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