Sciencemadness Discussion Board

Weird scent from electrolysis of sodium hydroxide solution. Any ideas as to what it could be?

itsallgoodjames - 20-11-2020 at 16:47

I was doing electrolysis of a solution of sodium hydroxide. Copper is being used as both the anode and cathode, as the intent of this is to produce copper hydroxide. It was going fine for a while, until it began to smell odd, somewhat like the smell of the dust burning off running vacuum tubes. My first thought was maybe it's chlorine impurities in the sodium hydroxide, as I used drain cleaner grade, but it doesn't smell of chlorine. My only idea is maybe it's from the flux I used soldering together the electrodes.

Any thoughts?

BromicAcid - 20-11-2020 at 18:00

My guess would be aresolized sodium hydroxide from the bubbling electrodes. During electrolysis of molten sodium hydroxide it was very prevalent.

itsallgoodjames - 20-11-2020 at 18:54

Hmm, that might be it. I'm not sure what aerosolized sodium hydroxide smells like, but there was definitely a bit of a stinging sensation.

Rhodanide - 23-11-2020 at 19:42

Quote: Originally posted by itsallgoodjames  
Hmm, that might be it. I'm not sure what aerosolized sodium hydroxide smells like, but there was definitely a bit of a stinging sensation.


Maybe you're smelling your sinus flesh being turned into soap! oooOOOooOOOhhhhhHHH!!
Hah.

But in all real seriousness, Bromic is probably right. Aerosols do have smells to them. Back in my "very stupid" days of home chemistry, I remember how aerosol-ized Cobalt and Nickel salt solutions smelled. Of course, my dumb young ass didn't know the potential danger of that. Aerosols suck, don't huff them, friend! Be safe.

macckone - 25-11-2020 at 09:32

drain cleaner often has fragrance in it. no clue why but it does.
between aerosols and god knows what impurities just keep that stuff covered and don't sniff it.

MidLifeChemist - 25-11-2020 at 10:32

Quote: Originally posted by Rhodanide  

But in all real seriousness, Bromic is probably right. Aerosols do have smells to them. Back in my "very stupid" days of home chemistry, I remember how aerosol-ized Cobalt and Nickel salt solutions smelled. Of course, my dumb young ass didn't know the potential danger of that. Aerosols suck, don't huff them, friend! Be safe.


Out of curiosity, how did you aerosol-ize Cobalt and Nickel salts solutions?

HydrogenSulphate - 25-11-2020 at 11:31

Quote: Originally posted by MidLifeChemist  
Quote: Originally posted by Rhodanide  

But in all real seriousness, Bromic is probably right. Aerosols do have smells to them. Back in my "very stupid" days of home chemistry, I remember how aerosol-ized Cobalt and Nickel salt solutions smelled. Of course, my dumb young ass didn't know the potential danger of that. Aerosols suck, don't huff them, friend! Be safe.


Out of curiosity, how did you aerosol-ize Cobalt and Nickel salts solutions?


There's one such scenario I can think of: if you are preparing the metal salts by the carbonate-dilute acid reaction, the vigorous effervescence as carbon dioxide gas is given off can generate a fine mist or aerosol. It is a good idea to cover the reaction flask or beaker with a watch glass or similar to contain the aerosol, especially if the salts being prepared from the carbonate and dilute acid contain Co, Cu, Ni, Cr, Ba, Pb, etc, etc, etc, ions.

EthidiumBromide - 25-11-2020 at 12:31

Or reactions involving hydrogen peroxide, where it will decompose generating bubbles of oxygen - generally, any reaction which leads to effervescence of the mixture.

TriiodideFrog - 1-12-2020 at 04:18

Maybe for some reason, chlorine gas started to form? I dunno.

itsallgoodjames - 1-12-2020 at 08:46

I can't think of anywhere the chlorine would come from though. It also doesn't really smell of chlorine. More like burning dust. I imagine bromicacid is probably right, it's probably my nose (and everyone else in the house's noses) turning to soap.

Errata - 14-12-2020 at 12:31

Safer alternative method for making copper hydroxide is just electrolysis of sodium or magnesium sulfate with same copper electrodes. Have tried this myself and it works really well, however a small amount of copper does end up electroplating instead of precipitating. Magnesium sulfate is available OTC in bulk, much cheaper (and probably purer) than drain cleaner.

itsallgoodjames - 15-12-2020 at 06:48

I recently received 5lbs of copper sulfate. The point of the copper hydroxide was to be used as a source of copper for copper salts, without having to first go through copper nitrate. I was at the time out of copper sulfate, and I wanted to make copper complexes. Now that I once again have copper sulfate, I no longer need the copper hydroxide.