video tutorial Hypophosphorus acid preparation

Name: video tutorial - Hypophosphorus acid preparation
Uploaded: 2025-12-11T09:03:44.282Z
Duration: 7 min 32 s
Description: we recently acquired an interesting chemical sodium hypophosphate it's the...sodium salt of hypophosphorus acid which can apparently be used together with iodine instead

Subject: sodium hypophosphate (sodium salt of hypophosphorus acid) and its use with iodine to reduce alcohols to alkanes; aim to prepare the acid from the salt.
Method and yield: reacted 100 g of sodium hypophosphate dihydrate with two portions of concentrated HCl to form sodium chloride and hypophosphorus acid; isolated about 40 g of NaCl (expected ~47 g).
Filtrate contained hypophosphite/hydrogen ions; concentrated filtration and partial distillation produced a strong hypophosphorus acid solution; observed pale yellow filtrate density ~1.35 g/mL (theory ~1.49).
Test of reducing power: added iodine; reduction occurred, described as working well (perhaps too well).
Thermal test: heating the acid caused condensation, slight boiling, and a tiny explosion, indicating hazardous decomposition to phosphine; cautioned about reflux safety.
Final steps: evaporated liquid to dryness; noted reactive hazards—upon heating (~150°C) large clouds of phosphorus pentoxide form as phosphine gas ignites in air; plan to test reduction of an alcohol in a future video.
Overall note: demonstration emphasizes the reactivity and safety concerns of hypophosphorus acid/phosphine formation; stay tuned for further results.