Sciencemadness Discussion Board

Sodium Carbonate - strange stuff! Dissolved in room temp H2O then crystalized

RogueRose - 24-4-2016 at 13:30

I'm not exactly sure what's going on with the sodium carbonate but I added 15g to 40ml of water and it dissolved while heating up the water. After about 4 hours, it almost all crystalized into clearish crystals while the starting crystals where solid white (I'm 99% sure it was monohydrate).

I'm guessing it converted to some other hydrate, not sure which, but is there a way to get it to dissolve back into the water without adding a lot more water? This stuff is hard to figure out b/c some of it dissolves better at higher temps, others at lower temp.

[Edited on 24-4-2016 by RogueRose]

solitanze - 24-4-2016 at 13:50

From the sodium carbonate/water phase diagram, what you have is the decahydrate.

Heat the solution a little and it should dissolve again.