Draeger
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White gas from reaction of HCl with impure CuO?
So, I made some not really pure copper powder a few days ago, and yesterday I roasted it to convert it to copper(II)-oxide. I then wanted to convert
the copper(II)-oxide into copper(II)-chloride. Thus, I poured some 32% HCl onto the copper oxide. Then, immediately, a white gas or mist came off. In
a panic, since I didn't know what this could be, I simply threw in a bit of baking soda to neutralize it.
Does anyone know what this was?
Collected elements:
Al, Cu, Ga, C (coal), S, Zn, Na
Collected compounds:
Inorganic:
NaOH; NaHCO3; MnCl2; MnCO3; CuSO4; FeSO4; aq. 30-33% HCl; aq. NaClO; aq. 9,5% ammonia; aq. 94-96% H2SO4; aq. 3% H2O2
Organic:
citric acid, sodium acetate, sodium citrate, petroleum, mineral oil
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Bedlasky
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It is gaseous HCl. Reaction between conc. HCl and CuO is exothermic and some HCl escaped from solution due to it.
Even when you pour some water in to the conc. HCl, there is some gaseous HCl formation.
[Edited on 19-4-2020 by Bedlasky]
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Arcaeca
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Mood: brøthér, can you spare some B̲̺̹̙̑́̓́ͧ̎ͭ̈́͜L̰̦̼̻͈͖̺͔̇̇̿ͪ̓̃̽ͦŲ̘̲̻͔̀͌͑͑̊͛̑̀͊̕E̐ͮͯ͆̔̾͘͏҉̥̫
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That, and 32% is well above the point where HCl fumes, reaction or not. But theoretically the reaction of HCl and CuO is a double displacement
reaction that would gives off H2O, some of which would be released as steam if it gets hot enough.
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mackolol
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Hydrochloric acid tends to fume at even lower concentrations and especially during reactions with something.
Yesterday, when I poured crude mother liquor from propiophenone synthesis into hydrochloric acid, it created so big cloud of HCl that it burned my
hands and it was technical grade 31%.
Reason why HCl vapors are white, is that the gas is "damp" it contains water vapors maybe even something steam - like in it, which make it appear
white.
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