Quick chemistry question

superart · 03-31-2004, 08:58 PM

Tonight my school had like a special chem. thing sponsored by the National chem. Association or, whatever. We had the chance to bring a bottle, or a bunch of bottles, and coat the inside with silver.

Basically, we were supposed to wash the inside out with nitric acid. Then pour the acid out and rinse with water. Then pour in hot water to heat the glass up. After some time, we were to pour the hot water out and pour in some silver-nitrate and splash it around. This would coat the inside with silver, and make the outside look like like a mirror. It was pretty cool.

Now, on to my question. For my bottle, I decided to bring in a Capt. Morgan Parrot Bay Coconut Flavored Rum bottle. I Followed instructions pretty much to the letter. Got a rubber stopper, poured in some Nitric acid, closed the stopper, and started to swoosh it around. Fore everyone else's bottle, nothing interesting happened.

However in my bottle, apparently the nitric acid started to react with the alcohol left over from the rum and turn yellow. Also, a really thick yellowish-orangeish-brownish gas started to form and filled the entire bottle.

I decided to not do the silver thing, since the toxic-looking brown gas made it look much cooler. So, I just kept the rubber stopper in, and took it back to my dorm. Once I got home, for a safety measure, I covered the stopper and rim of the bottle with epoxy.

My question is, does anyone know what this brown gas is?

I assume it is poisonous/toxic since it looks a lot like Nitrogen Dioxide (NO2). I will try to find someone with a digital camera to take a pic and post it. However, the gas itself looks something like this:

Thanks, I appreciate if anyone could help me out here.

TerraMex · 03-31-2004, 09:19 PM

Nasty. Still, brown colour is a dead giveaway of NO2 gas.

Nitric Acid (HNO3), i think, reacted with water:

3 NO2 + H2O <--> 2 HNO3 + NO

Or something. Dont think it was the alcohol.
Then again, my last chemistry class was a long time ago.

ChemMan · 03-31-2004, 09:43 PM

Yep, that's gotta be NOX gas in there. Assuming that you didn't wash the bottle out before you put the nitric acid in there, any oxidizable material in the bottle (not just the alcohol) could have produced that gas.

Pretty cool.

superart · 03-31-2004, 11:02 PM

Yea, Im just surprised that I was the only person, out of like 100 or 150 people that had this happen.

Most people had like a whiteish-clearish gas coming off, but I'm pretty sure that was just the nitric acid evaporating off.

TerraMex · 04-01-2004, 01:25 AM

Maybe not.
Maybe some CO2 formation.

superart · 04-01-2004, 01:54 AM

Could be.
:shrug:

03-31-2004, 08:58 PM	#1
superart Cooling Savant Join Date: Mar 2002 Location: FL Posts: 787	Quick chemistry question Tonight my school had like a special chem. thing sponsored by the National chem. Association or, whatever. We had the chance to bring a bottle, or a bunch of bottles, and coat the inside with silver. Basically, we were supposed to wash the inside out with nitric acid. Then pour the acid out and rinse with water. Then pour in hot water to heat the glass up. After some time, we were to pour the hot water out and pour in some silver-nitrate and splash it around. This would coat the inside with silver, and make the outside look like like a mirror. It was pretty cool. Now, on to my question. For my bottle, I decided to bring in a Capt. Morgan Parrot Bay Coconut Flavored Rum bottle. I Followed instructions pretty much to the letter. Got a rubber stopper, poured in some Nitric acid, closed the stopper, and started to swoosh it around. Fore everyone else's bottle, nothing interesting happened. However in my bottle, apparently the nitric acid started to react with the alcohol left over from the rum and turn yellow. Also, a really thick yellowish-orangeish-brownish gas started to form and filled the entire bottle. I decided to not do the silver thing, since the toxic-looking brown gas made it look much cooler. So, I just kept the rubber stopper in, and took it back to my dorm. Once I got home, for a safety measure, I covered the stopper and rim of the bottle with epoxy. My question is, does anyone know what this brown gas is? I assume it is poisonous/toxic since it looks a lot like Nitrogen Dioxide (NO2). I will try to find someone with a digital camera to take a pic and post it. However, the gas itself looks something like this: Thanks, I appreciate if anyone could help me out here. __________________ When you do things right, people won't be sure youv'e done anything at all. Looking to buy/trade for used Deep Fryer and Vacume Pack Sealer.

03-31-2004, 09:19 PM	#2
TerraMex Cooling Savant Join Date: Nov 2002 Location: Portugal, Europe Posts: 870	Nasty. Still, brown colour is a dead giveaway of NO2 gas. Nitric Acid (HNO3), i think, reacted with water: 3 NO2 + H2O <--> 2 HNO3 + NO Or something. Dont think it was the alcohol. Then again, my last chemistry class was a long time ago. __________________ "we need more cowbell."

03-31-2004, 09:43 PM	#3
ChemMan Cooling Neophyte Join Date: Jan 2003 Location: New Jersey, USA Posts: 15	Yep, that's gotta be NOX gas in there. Assuming that you didn't wash the bottle out before you put the nitric acid in there, any oxidizable material in the bottle (not just the alcohol) could have produced that gas. Pretty cool. __________________ AthlonXP 1600+ Soyo KT400 dragon ultra 512 megs Samsung DDR333 PowerColor 9700 Antec SOHO case other junk

03-31-2004, 11:02 PM	#4
superart Cooling Savant Join Date: Mar 2002 Location: FL Posts: 787	Yea, Im just surprised that I was the only person, out of like 100 or 150 people that had this happen. Most people had like a whiteish-clearish gas coming off, but I'm pretty sure that was just the nitric acid evaporating off. __________________ When you do things right, people won't be sure youv'e done anything at all. Looking to buy/trade for used Deep Fryer and Vacume Pack Sealer.

04-01-2004, 01:25 AM	#5
TerraMex Cooling Savant Join Date: Nov 2002 Location: Portugal, Europe Posts: 870	Maybe not. Maybe some CO2 formation. __________________ "we need more cowbell."

04-01-2004, 01:54 AM	#6
superart Cooling Savant Join Date: Mar 2002 Location: FL Posts: 787	Could be. :shrug: __________________ When you do things right, people won't be sure youv'e done anything at all. Looking to buy/trade for used Deep Fryer and Vacume Pack Sealer.

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