Sciencemadness Discussion Board

Sodium oxide via decomposition of Sodium sulfate - would it work?

Merryp - 6-10-2019 at 04:24

I think it's fair to assume that sulfur dioxide would be the first thing to go upon heating to decomposition temperature in an open crucible (or distillation apparatus, if you

Question is how the rest of the molecule would act. If it's elemental sodium, that'd probably start evaporating as well, possibly reacting with the SO2 again.
If it's going to form sodium oxide immediately, that'd be way more convenient, since it'll remain solid at that temperature range.

I think the latter case is probable, but I'm not entirely sure. Can sodium oxide be easily obtained by roasting the sulfate?

rockyit98 - 6-10-2019 at 05:07

2NaOH------(HEAT)-------->Na2O+H20 works
but molten NaOH react with glass, Porcelain ,aluminium,stainless steel ,nickel,graphite must use
Magnesia(MgO) container aka crucible. if O2 free copper might work.

Na2CO3---(HEAT)------>Na2O +CO2
is the best so far. adding a vacuum pumps help a lot.

Tsjerk - 6-10-2019 at 05:11

Sulfur in sulfate is in oxidation state VI. It won't change upon heating. Therefore you won't get SO2.

No element will change in oxidation state. Guess again.

But then again, the temperature this will happen is high. And the reactants at that temp are quite reactive.

12thealchemist - 6-10-2019 at 05:56

Sodium sulphate can be thermally decomposed by heating, but this starts at around 1000°C and is very slow at this temperature, becoming appreciable nearer 1400°C. At these extremes, the normally-evolved sulphur trioxide from the sulphate anion itself thermally decomposes into oxygen and sulphur dioxide. Sodium oxide is the solid product, but for the amateur to reach these temperatures on any sensible scale, I wish him luck.