The discussion centers on identifying sodium carbonate and sodium bicarbonate, exploring various methods for differentiation, including pH measurement, taste tests, and thermal decomposition. Participants share personal anecdotes and technical insights related to the identification of these compounds.
Participants express various methods for identifying the two compounds, but there is no consensus on a single best approach. The discussion includes both agreement on certain identification methods and differing opinions on the nomenclature of bicarbonate.
Some methods proposed depend on specific conditions, such as the availability of laboratory equipment for titration or the interpretation of pH results. The discussion also touches on historical naming conventions that may not align with modern terminology.
This discussion may be of interest to chemistry students, educators, and hobbyists looking to understand the properties and identification methods of sodium carbonate and sodium bicarbonate.
This takes me back more than fifty years. My ex-wife tried sodium carbonate in a recipe for scones. They tasted of soap!! Daft thing was that we tried three times before realising what was our mistake!!!Rajini said:TL;DR Summary: Identification of sodium carbonate and bicarbonate
Dear all,
How to identify sodium carbonate and sodium bicarbonate? I have these two powders, and did not label.
Thanks for your reply.
Cheers, Rajini
Both will fizz if a sample of each is mixed with an acid (using vinegar, maybe). They each will give a different titration curve, so at least if you are in a fitting laboratory situation, you'll find a suggestion of two endpoints for the carbonate, and one endpoint for the bicarbonate. (That is, titrating with an acid titrant.)Rajini said:TL;DR Summary: Identification of sodium carbonate and bicarbonate
Dear all,
How to identify sodium carbonate and sodium bicarbonate? I have these two powders, and did not label.
Thanks for your reply.
Cheers, Rajini
Thats right. A little of both in individual test tubes…. heat gently with bunsen burner. The one that seems to “boil” is the bicarb.hilbert2 said:NaHCO##_3## decomposes and produces carbon dioxide bubbles when heated near the boiling point of water:
https://www.stem.org.uk/system/file...cy_files_migrated/31929-catalyst_24_3_579.pdf
This reaction doesn't happen with sodium carbonate.
To complete the 'School' experiment, the gas that bubbles off could be collected in an inverted tube ('downward displacement of water') and it will extinguish a burning match etc.chemisttree said:Thats right. A little of both in individual test tubes…. heat gently with bunsen burner. The one that seems to “boil” is the bicarb.
He has both materials.Vanadium 50 said:Just out of curisity, why is it bicarbonate if there is only the one?
TL;DR SummaryIdentification of sodium carbonate and bicarbonate
Dear all,
How to identify sodium carbonate and sodium bicarbonate? I have these two powders, and did not label.
Thanks for your reply.
Cheers, Rajini
The OP's notation is 'old fashioned' and it's what I learned at School. The Bi, ate, ite, ide etc. parts of the name are a code to tell what's what but it's limited and not intuitive. I was told this by a school lab tech not long ago. There is a new system which is more complicated but describes much more complex compounds. This link has many examples of formulae and common names. It doesn't seem to have any logic to me except for very simple compounds. No doubt the PF Chemists will put name right.Vanadium 50 said:Just out of curiosity, why is it bicarbonate if there is only the one?
The whole process of early Chemistry was pretty arcane and (just as today) very painstaking.chemisttree said:Same is true of the sodium salt of bisulfite (HSO3)- and sulfite (SO3)-2.