Timeline for What is this copper compound I made?
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
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| Apr 23, 2020 at 22:50 | comment | added | HaLo2FrEeEk | I guess I'll add sulfuric acid little by little with stirring. This really is just an experiment with leftover chemicals so... | |
| Apr 23, 2020 at 15:20 | comment | added | Maurice | To recover copper carbonate, the excess carbonate must be destroyed, by adding an acid. The trouble is : first the excess carbonate ions will produce huge amounts of CO2. Then the anion $\ce{[Cu(CO_3)_2]^{2-}}$ will be decomposed and the malachite precipitate will soon appear again. But it is difficult to know with some precision the amount of acid necessary to obtain malachite quantitively, because if an excess of acid is added, the malachite will be dissolved and at the end you will obtain a $\ce{Cu^{2+}}$ solution like in the very beginning of your experiments. | |
| Apr 23, 2020 at 8:48 | comment | added | Maurice | Your white precipitate may be sodium hydrogenocarbonate $\ce{NaHCO_3}$ which is not very soluble in water : $6.9$ g in $100$ mL, and less in $\ce{Na_2CO_3}$ solutions. This substance appears in $\ce{Na_2CO_3}$ solution exposed to air and/or to $\ce{CO_2}$ | |
| Apr 23, 2020 at 2:28 | comment | added | HaLo2FrEeEk | Wow, thank you for the very specific answer! I'm wondering, is there a way to somehow recover the copper carbonate/anion from the filtrate? After filtering I've let it sit in a wide mouth jar covered with a coffee filter and there's some white precipitate at the bottom and fractal-tree looking crystals crawling up the sides. | |
| Apr 23, 2020 at 2:24 | vote | accept | HaLo2FrEeEk | ||
| Apr 22, 2020 at 20:04 | history | edited | Maurice | CC BY-SA 4.0 |
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| Apr 22, 2020 at 19:43 | history | edited | Maurice | CC BY-SA 4.0 |
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| Apr 22, 2020 at 10:16 | history | answered | Maurice | CC BY-SA 4.0 |