Live in 5 minutes: Refining the Starch Method for producing Sodium Nitrite
Added 2025-01-06 19:36:50 +0000 UTCI need sodium nitrite (NaNO2) for part of the chemistry I'll be using in my next project. In this stream, I'll be attempting to refine an interesting process which uses starch to convert more common nitrate salts into the harder to find nitrite.
Comments
Oh, btw, N(SO3Na)3 is already oxidated. You don’t need to add extra oxygens there. To me this is unclear how it could form in an aqueous solution and how it would selectively react with the hydroxyl groups in the polysaccharide. A well known method of producing sulfated esters of various alcohols including polysaccharides is to dissolve sulfamic acid, urea and said polysaccharides in a minimal amount of water and heat the solution to force it to liberate water. Without a secondary solvent this tends to foam a lot. You can use secondary solvents with a BP higher than water such as Dimethyl Formamide. At the end you will get the ammonium salt of the sulfated polysaccharide alcohol. Alternative methods of producing sulfated polysaccharides are: 1.) Reaction with chlorosulfonic acid salts in a stable tertiary amine solution such as triethylamine. (preferred laboratory and way) 2.) Chlorination by dissolving the polysaccharide in ice cold saturated solution of zinc chloride in concentrated hydrochloric acid followed by stirring for a few hours at below 10C. This replaces hydroxyl groups in the polymer with chloride groups. This is followed by washing the chlorinated polymer with water and then adding it to an acidified sulfuric solution of silver alum. The solution contains silver and acid sulfate ions which replace the chloride with sulfate groups. Silver chloride precipitates out of solution as the sulfated polymer becomes more soluble.
RoboCommie
2025-02-22 04:24:12 +0000 UTCEven the amateur chemistry community has difficulty with making nitrite salts. One of the most reliable high yield methods is melting sodium nitrate over molten lead metal which is used as the reducing agent which converts the nitrate to nitrite but stops at nitrite… but it uses lead… soooo… yea 😬 A method that is less known and doesn’t require nitrate salts is by the copper catalysed oxidation of ammonia. Basically, make copper hydroxide by adding concentrated copper sulfate solutions to dilute solutions of sodium hydroxide. Then dissolve that copper hydroxide in a minimal amount of highly concentrated ammonia hydroxide to make a dark blue solution of Schweizer's reagent. Put that solution in a container, preferably under a pure oxygen atmosphere saturated with water and ammonia and stir it at 30C (could use a magnetic stirrer) for at least 24h. The copper spontaneously oxidises the ammonia to a tetraamine copper nitrite complex. Add this in a sodium hydroxide solution which starts separating ammonia from the copper complex, forming sodium nitrite and copper hydroxide. Filter the copper hydroxide before heating. The water in the solution should be just enough to recover the ammonium hydroxide by distillation without diluting it. The remaining mixture contains sodium hydroxide and sodium nitrite. To purify the nitrite further, you can either leech it out of the sodium hydroxide and nitrite powder mixture with dry diethyl ether using a soxhlet extractor or make a solution in ethanol, make another solution of silver nitrate in ethanol and combine those two to precipitate pure silver nitrite. You don’t need nitrite in my opinion, but those are the ways to do it.
RoboCommie
2025-02-22 02:52:32 +0000 UTCI think I'll quit doing streams in the future about untested chemistry. It never seems to go very well. I'll at least wait until I've tried a thing once or twice before jumping on. Thanks everyone for bearing with me as I figure this streaming stuff out!
NightHawkInLight
2025-01-06 23:49:46 +0000 UTC
