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Ramium
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Copper phosphate synthesis useing phosphoric acid???
I plan to make copper phosphate from copper carbonate and phosphoric acid.
I heard phosphoric acid is sold as a rust remover so i looked in my local hardware store and found some.it said it was 500g phosphoric acid per litre
What percentage phosphoric acid is that??
And would it work in the experiment??
Any help would be appreciated
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Ramium
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Here is a link to the video I am using
http://youtu.be/k4k92mmo3_Q
[Edited on 1-2-2015 by Ramium]
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Volanschemia
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500g of H3PO4 equals 265mL (Density = 1.885, 500/1.885 = 265..).
So therefore 500g/L would equal 26.5% Phosphoric Acid.
I'm not sure if you'd be able to use such a low concentration in the reaction. It might work, but you'd have to recalculate the stoichiometry. You
could try heating the mixture up to 110 degrees Celsius to boil off some of the water (Phosphoric Acid boils at 158 degrees Celsius). I'm not sure if
it forms an azeotrope though so it might stop working at a certain point.
If you have access to Phosphorus(V) Oxide you can make Phosphoric Acid by adding it to water.
"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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Ramium
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Can i buy phosphorus v oxide if not can i make it?
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Ramium
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I looked at phosphorus v oxide on wikipedia it says it is made by burning phosphorus
White phosphorus or red phosphorus?
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Volanschemia
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Phosphors(V) Oxide can be bought here but is is expensive.
From Wikipedia:
In the thermal process, the phosphorus pentoxide obtained by burning white phosphorus was dissolved in dilute phosphoric acid to
produce concentrated acid.
If you have access to white Phosphorus you could make conc. Phosphorus Acid by burning the Phosphorus under a stream of Oxygen then dissolving it in
the dilute OTC Phosphoric Acid.
A simpler option would be to just buy the Phosphoric Acid from here.
"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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unionised
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Or you could just use the phosphoric acid you have already got.
The reaction might be a bit slower because of the extra water, but it will still work.
You will need to use more of it too (or less copper carbonate).
Messing about with white phosphorus and its pentoxide isn't fun.
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blogfast25
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Quote: Originally posted by TheAustralianScientist  | 500g of H3PO4 equals 265mL (Density = 1.885, 500/1.885 = 265..).
So therefore 500g/L would equal 26.5% Phosphoric Acid.
I'm not sure if you'd be able to use such a low concentration in the reaction. It might work, but you'd have to recalculate the stoichiometry. You
could try heating the mixture up to 110 degrees Celsius to boil off some of the water (Phosphoric Acid boils at 158 degrees Celsius). I'm not sure if
it forms an azeotrope though so it might stop working at a certain point.
If you have access to Phosphorus(V) Oxide you can make Phosphoric Acid by adding it to water. |
Correct and yet baloney too.
He knows the solution contains 500 g H3PO4 per litre of solution.
The molar mass of H3PO4 is 98 g/mol, so 500 g = 500/98 = 5.1 mol. The solution is thus 5.1 mol H3PO4 per litre or 5.1 M H3PO4.
That's all you need to know and 5.1 M is strong enough for most purposes.
For chemistry molarity is far more useful than w%.
Ramium, how do you plant to prepare that copper phosphate?
Edit:
Ooops, didn't see that bit about copper carbonate, my bad.
It's a bad idea though. Dissolving an insoluble compound (copper carbonate) in an acid to obtain another insoluble compound (copper phosphate) is a
recipe for occlusion: bits of copper carbonate stuck in the copper phosphate.
Better to dissolve the copper carbonate in minimal amounts of HCl or H2SO4, then add the required amount of phosphoric acid to precipitate the copper
phosphate.
[Edited on 1-2-2015 by blogfast25]
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Ramium
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Thanks. I would like to get some reasonably pure phosphoric acid if possible i heard that
Brewery supply stores sell it So i will hav a look i one today.if i cant find some then maybe i will just go with that highly inpure stuff i found in
the hardware store
[Edited on 1-2-2015 by Ramium]
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blogfast25
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How do you know the hardware stuff is 'highly impure'?
Are you just assuming? Does the label state any other ingredients (other than water and phosphoric acid)? What's its colour for instance?
[Edited on 1-2-2015 by blogfast25]
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Ramium
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| Quote: Originally posted by blogfast25 | | Quote: Originally posted by TheAustralianScientist | 500g of H3PO4 equals 265mL (Density = 1.885, 500/1.885 = 265..).
So therefore 500g/L would equal 26.5% Phosphoric Acid.
I'm not sure if you'd be able to use such a low concentration in the reaction. It might work, but you'd have to recalculate the stoichiometry. You
could try heating the mixture up to 110 degrees Celsius to boil off some of the water (Phosphoric Acid boils at 158 degrees Celsius). I'm not sure if
it forms an azeotrope though so it might stop working at a certain point.
If you have access to Phosphorus(V) Oxide you can make Phosphoric Acid by adding it to water. |
Correct and yet baloney too.
He knows the solution contains 500 g H3PO4 per litre of solution.
The molar mass of H3PO4 is 98 g/mol, so 500 g = 500/98 = 5.1 mol. The solution is thus 5.1 mol H3PO4 per litre or 5.1 M H3PO4.
That's all you need to know and 5.1 M is strong enough for most purposes.
For chemistry molarity is far more useful than w%.
Ramium, how do you plant to prepare that copper phosphate?
Edit:
Ooops, didn't see that bit about copper carbonate, my bad.
It's a bad idea though. Dissolving an insoluble compound (copper carbonate) in an acid to obtain another insoluble compound (copper phosphate) is a
recipe for occlusion: bits of copper carbonate stuck in the copper phosphate.
Better to dissolve the copper carbonate in minimal amounts of HCl or H2SO4, then add the required amount of phosphoric acid to precipitate the copper
phosphate.
[Edited on 1-2-2015 by blogfast25] |
i hav some HCL so i will dissolve the copper carbonate in that. But
wouldent that make copper chloride?????
[Edited on 1-2-2015 by Ramium]
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cyanureeves
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i have phosphoric acid and i put some copper in a little bit of phosphoric acid and not much happened until i added hydrogen peroxide.i got a blue
solution over time that was oily looking.was that copper phosphate i produced?
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Ramium
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| Quote: Originally posted by blogfast25 |
How do you know the hardware stuff is 'highly impure'?
Are you just assuming? Does the label state any other ingredients (other than water and phosphoric acid)? What's its colour for instance?
[Edited on 1-2-2015 by blogfast25] |
it says 500g/l isn't that highly impure??
[Edited on 1-2-2015 by Ramium]
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blogfast25
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OF COURSE IT DOESN'T MEAN THAT.
It simply means that your hardware stuff contains 500 g of H3PO4 per litre of solution, the rest being water.
You don't need (or want!) 100 % H3PO4 for what you are trying to do.
By 'impuriries' here in this context is meant: substances present in the H3PO4/water mixture OTHER than H3PO4 or H2O.
The water in that solution doesn't impede using that solution in your application, quite the opposite actually.
Tell me, if you ever plan make some sulphates, will you only want to use pure, 100 % H2SO4? I hope not because that would be ABSURD.
Of course there are applications for 100 % H3PO4 too, it's just not needed here. 5.1 M H3PO4 will do just fine.
Water here is not an 'impurity', it's a solvent.
[Edited on 1-2-2015 by blogfast25]
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BromicAcid
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I remember purchasing some industrial stainless steel cleaner that was ca. 25% phosphoric acid. However, when I went to actually do experiments with
it it had such a combination of inhibitors and surfactants that I either ended up with a beaker of foam or had no visible reaction 
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Volanschemia
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| Quote: Originally posted by blogfast25 |
Correct and yet baloney too.
He knows the solution contains 500 g H3PO4 per litre of solution.
The molar mass of H3PO4 is 98 g/mol, so 500 g = 500/98 = 5.1 mol. The solution is thus 5.1 mol H3PO4 per litre or 5.1 M H3PO4.
That's all you need to know and 5.1 M is strong enough for most purposes.
For chemistry molarity is far more useful than w%.
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I know that M is more useful than % but if you recall the opening post:
| Quote: |
I plan to make copper phosphate from copper carbonate and phosphoric acid.
I heard phosphoric acid is sold as a rust remover so i looked in my local hardware store and found some.it said it was 500g phosphoric acid per litre
What percentage phosphoric acid is that??
And would it work in the experiment??
Any help would be appreciated
|
[Edited on 2-2-2015 by TheAustralianScientist]
"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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Ramium
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| Quote: Originally posted by blogfast25 |
OF COURSE IT DOESN'T MEAN THAT.
It simply means that your hardware stuff contains 500 g of H3PO4 per litre of solution, the rest being water.
You don't need (or want!) 100 % H3PO4 for what you are trying to do.
By 'impuriries' here in this context is meant: substances present in the H3PO4/water mixture OTHER than H3PO4 or H2O.
The water in that solution doesn't impede using that solution in your application, quite the opposite actually.
Tell me, if you ever plan make some sulphates, will you only want to use pure, 100 % H2SO4? I hope not because that would be ABSURD.
Of course there are applications for 100 % H3PO4 too, it's just not needed here. 5.1 M H3PO4 will do just fine.
Water here is not an 'impurity', it's a solvent.
[Edited on 1-2-2015 by blogfast25] |
sorry i am new to chemistry. I will just use the 500 /l stuff then.
[Edited on 2-2-2015 by Ramium]
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Volanschemia
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| Quote: | sorry i am new to chemistry. I will just use the 500 /l stuff then.
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No need to apologize. Everyone started at some point and I think SOME people need to remember that.
I think you could use the 5.1M stuff. You'll just need to recalculate the stoichiometry. Would you like me to show you how?
I gather you're planning on making Copper(II) Phosphate? Not Copper(I) Phosphate?
[Edited on 2-2-2015 by TheAustralianScientist]
[Edited on 2-2-2015 by TheAustralianScientist]
"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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Zombie
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At the risk of sounding "simple" couldn't you use a desiccant such as silica gell or Calcium Chloride to remove some of the water
They tried to have me "put to sleep" so I came back to return the favor.
Zom.
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blogfast25
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Do that by all means but make it educational, i.o.w. let the OP do most of the work, so that at least he learns as much as possible.
He needs to acquaint himself with stoichiometry, moles and molarity at a very minimum.
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blogfast25
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| Quote: Originally posted by Zombie | | At the risk of sounding "simple" couldn't you use a desiccant such as silica gell or Calcium Chloride to remove some of the water
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There is no need whatsoever to remove some or all of the water. The water here is in fact beneficial or at least doesn't hurt a fly.
Removing water here would be done by simple evaporation of it, because H<sub>3</sub>PO<sub>4</sub> has a much higher BP than
water. About 75 % acid can be obtained this way.
Silica gel and CaCl<sub>2</sub> (anh.) are limited in how much water they can absorb. They are mostly used to dry stuff that is already
fairly dry, not stuff that's floating in an ocean of water.
[Edited on 2-2-2015 by blogfast25]
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Amos
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If anyone's making copper phosphate just skip all of this and precipitate it using a water-soluble copper salt and sodium phosphate. Not only is
sodium phosphate cheap OTC, it can very easily be made simply by neutralizing sodium bicarbonate or carbonate with phosphoric acid, and it's
strikingly easy to crystallize, too.
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blogfast25
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| Quote: Originally posted by No Tears Only Dreams Now | | If anyone's making copper phosphate just skip all of this and precipitate it using a water-soluble copper salt and sodium phosphate. Not only is
sodium phosphate cheap OTC, it can very easily be made simply by neutralizing sodium bicarbonate or carbonate with phosphoric acid, and it's
strikingly easy to crystallize, too. |
Sure but since he as access to cheap 5.1 M H<sub>3</sub>PO<sub>4</sub> he might as well use that.
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Amos
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| Quote: Originally posted by blogfast25 | | Quote: Originally posted by No Tears Only Dreams Now | | If anyone's making copper phosphate just skip all of this and precipitate it using a water-soluble copper salt and sodium phosphate. Not only is
sodium phosphate cheap OTC, it can very easily be made simply by neutralizing sodium bicarbonate or carbonate with phosphoric acid, and it's
strikingly easy to crystallize, too. |
Sure but since he as access to cheap 5.1 M H<sub>3</sub>PO<sub>4</sub> he might as well use that. |
Well doing it this way, either the end product will contain leftover copper carbonate or it will have to be washed of syrupy leftover phosphoric acid
and any possible contaminants in the product. Sure, a solution of simply phosphoric acid and water sounds nice but there might be more to it.
Oh, one more thing. The effervescence produced as a result of carbon dioxide formed is going to be a real pain given the viscosity of phosphoric acid
and the fact that there's a bunch of insoluble material in the way.
[Edited on 2-2-2015 by No Tears Only Dreams Now]
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blogfast25
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| Quote: Originally posted by No Tears Only Dreams Now |
Well doing it this way, either the end product will contain leftover copper carbonate or it will have to be washed of syrupy leftover phosphoric acid
and any possible contaminants in the product. Sure, a solution of simply phosphoric acid and water sounds nice but there might be more to it.
Oh, one more thing. The effervescence produced as a result of carbon dioxide formed is going to be a real pain given the viscosity of phosphoric acid
and the fact that there's a bunch of insoluble material in the way.
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You don't seem to have read this thread fully.
I've already recommended converting the copper basic carbonate to CuCl2 or CuSO4 first, to avoid problems of carbonate occlusion later on.
After that, basically dilute the Cu<sup>2+</sup> solution to about 1 M. Add the stoichiometric amount of 5.1 M H3PO4 to precipitate the
Cu<sub>3</sub>(PO<sub>4</sub> <sub>2</sub>.
Filter, wash and dry.
In a nutshell...
[Edited on 2-2-2015 by blogfast25]
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