okelly4408
Harmless
Posts: 2
Registered: 18-2-2013
Member Is Offline
Mood: No Mood
|
|
What Gas Was Produced?
Hello,
Recently I made a small amount of sodium nitrate by reacting sodium hydroxide and ammonium nitrate. After desiccating the solution and recrystalizing
the sodium nitrate I dissolved it in a bit of water. To this water I then added sodium bisulfate. When this was added it started to violently
effervescence. I am clueless in determining what this gas was. Any help is appreciated, thanks!
|
|
|
woelen
Super Administrator
Posts: 8014
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
This gas must be carbon dioxide. Probably you added excess NaOH, which leaves a solution of NaOH and NaNO3 (and NH3). After evaporation, NaOH and
NaNO3 remain, but the NaOH absorbs CO2 from the air and at the time when all is dry, all of it will have been converted to Na2CO3. The acid NaHSO4 is
strong enough to release CO2 from Na2CO3.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Recrystallise your product: NaNO3 and NaOH/Na2CO3 are fairly easy to separate that way (look uo their solubilities). Next time, try working nearer to
stoichiometric conditions.
|
|
|
okelly4408
Harmless
Posts: 2
Registered: 18-2-2013
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by woelen  | | This gas must be carbon dioxide. Probably you added excess NaOH, which leaves a solution of NaOH and NaNO3 (and NH3). After evaporation, NaOH and
NaNO3 remain, but the NaOH absorbs CO2 from the air and at the time when all is dry, all of it will have been converted to Na2CO3. The acid NaHSO4 is
strong enough to release CO2 from Na2CO3. |
Ah ok that makes sense. I did have the hydroxide in slight excess but I did not know that it could form sodium carbonate.. Thanks for the help though.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
