RogueRose
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Copper carbonates - Basic & Copper II - molar amounts
I was comparing some copper carbonates to CuO with regard to price at an online reseller, carbonate was $7.10/lb and CuO is $18.90/lb. It doesn't
state the type of carbonate but I thought I would be able to tell by the molar mass, and found something odd in wiki.
Wiki listing
CuCO3 = 123.55g/mol
Cu2(OH)2CO3 (basic copper carbonate) = 123.55
Now this is obviously wrong as per the weights.
Cu = 63.5g/mole
O = 16g/mole
C = 12g/mole
H = 1g/mole
So I have calculated that basic copper carbonate = ~221g/mole while the CuCO3 amount is correct.
When i calculate the difference in molar mass for CuO and basic copper carbonate & the price, it seems that the amounts are equal for equivelant
masses of copper in each compound, so that seems to mean my calculation is correct.
So, does anyone know how to submit a change to Wiki or have an account to do so?
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j_sum1
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CuCO3 does not exist. It is not stable. (This has been discussed before with blogfast stating the definitive word.)
There are two common basic carbonates of copper (II). The most easily produced and the one you are likely to see is malachite, CuCO3Cu(OH)2.H2O. But
the hydration can vary a bit. And you can get some azurite included in there as well.
Azurite is Cu3(CO3)2(OH)2.
So, the stiochiometry is not tidy.
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RogueRose
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Quote: Originally posted by j_sum1  | CuCO3 does not exist. It is not stable. (This has been discussed before with blogfast stating the definitive word.)
There are two common basic carbonates of copper (II). The most easily produced and the one you are likely to see is malachite, CuCO3Cu(OH)2.H2O. But
the hydration can vary a bit. And you can get some azurite included in there as well.
Azurite is Cu3(CO3)2(OH)2.
So, the stiochiometry is not tidy. |
Well then either way, the molar amounts are way off from the 123.5g listed. They have either 2 or 3 copper at 63.5g each, so the minimum would be
127g for Cu2 and 190.5g for Cu3 and then you have to add the hydroxide and carbonate to each of these. That was the point of saying the listing of the
molar amounts is not correct.
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Tsjerk
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It's Wikipedia, why don't you change them?
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Bert
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Mood: " I think we are all going to die. I think that love is an illusion. We are flawed, my darling".
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One more time:
Free information on the internet is often worth exactly what you paid for it.
Be the change you want to see.
Rapopart’s Rules for critical commentary:
1. Attempt to re-express your target’s position so clearly, vividly and fairly that your target says: “Thanks, I wish I’d thought of putting it
that way.”
2. List any points of agreement (especially if they are not matters of general or widespread agreement).
3. Mention anything you have learned from your target.
4. Only then are you permitted to say so much as a word of rebuttal or criticism.
Anatol Rapoport was a Russian-born American mathematical psychologist (1911-2007).
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RogueRose
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I was trying to find out how to change it, but I didn't see any place to make corrections. I'm still looking.
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Fulmen
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Top right of the page (desktop version): https://en.wikipedia.org/w/index.php?title=Copper(II)_carbonate&action=edit
We're not banging rocks together here. We know how to put a man back together.
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