Timeline for White granular substance from restaurant with interesting properties - what is it?
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 18, 2016 at 23:12 | vote | accept | Wharf Rat | ||
| Sep 18, 2016 at 20:56 | comment | added | Ilmari Karonen | @Buttonwood: I happened to have some lemon juice and NaOH lying around, so I tested it, and there is indeed a noticeable color change from yellow to orange. Adding clear vinegar reverses it, so it would seem that something in the juice is reversibly changing color with pH. | |
| Sep 18, 2016 at 17:08 | comment | added | Buttonwood | @JanDvorak both the Dutch as well as the German versions of wikipedia actually hold color photos of crystals of sodium citrate. Expectedly, they are colorless. | |
| Sep 18, 2016 at 17:04 | comment | added | John Dvorak | Wikipedia doesn't state the color for monosodium citrate or disodium citrate, and Google image search is too tolerant to be helpful as well. | |
| Sep 18, 2016 at 17:01 | comment | added | Buttonwood | @getafix and Elkal Anwa The stated observation of orange coloration is indeed a bit puzzling. Aqueous solutions of NaOH + (acetic or citric acid alone) should remain colorless. A lemon is more complex, a mixture. Currently, none of the said reagents are with me to probe it. | |
| Sep 18, 2016 at 12:09 | comment | added | Wharf Rat | Is there anything about NaOH (or perhaps inside this particular mixture) that, when mixed with lemon juice, could lead to an orange colour? | |
| Sep 18, 2016 at 11:51 | comment | added | orthocresol | (+1) My first thought was NaOH too. The only slight doubt I have is that the dissolution of NaOH is noticeably exothermic, as anybody who has tried to prepare a stock solution can verify. :) Of course, if you just dissolve a little bit of solid in a lot of water, you wouldn't be able to tell. | |
| Sep 18, 2016 at 11:42 | comment | added | getafix | Your answer makes sense, but how do you explain the orange colour when the powder was mixed with lemon juice? | |
| Sep 18, 2016 at 11:19 | history | answered | Buttonwood | CC BY-SA 3.0 |