Sciencemadness Discussion Board

Sodium hydrosulfite source ?

CycloRook - 29-3-2022 at 05:00

This seems to be rather ambiguous. Another name is Sodium dithionite and I saw several preparations that say it's 80% purity.

This confuses me as well as the chemical coming off as being common it seems rather expensive.

Does anyone have an idea where I can get this?

bobm4360 - 29-3-2022 at 11:11

If you are in the US, Rit Color Remover.

Dr.Bob - 29-3-2022 at 17:00

Where are you located?

clearly_not_atara - 29-3-2022 at 17:51

Dithionite is not particularly common, it just happens to be "easy" (but tricky) to prepare from common materials, so it gets mentioned a lot. Particularly if you are talking about how to do something in theory, and you need a reducing agent, you might say "well, dithionite will do it" but everyone is really going to use borohydride or Pd/H2 or Al/Hg or whatever.

AvBaeyer - 29-3-2022 at 18:43

I recently bought some from Unfortunately, the cost of shipping doubles the price since it is a "dangerous good." As for purity, 80-85% is typical, even from places like Aldrich. Keep in mind that good, water tight storage is important.

Dithionite is a particularly good reducing agent in several circumstances. There are several good reviews that can be found with a google search.


woelen - 29-3-2022 at 23:14

Dithionite is a strong reductor, capable of reducing copper(II) ions to metallic copper. It is unstable at neutral and acidic pH. Solutions in water quickly decompose, giving all kinds of sulfurous compounds (smelly). Solutions in dilute acids become orange and quickly precipitate elemental sulfur and become very smelly as well.

Be careful with dithionite. If it becomes damp, then it quickly is oxidized by oxygen from air in an exothermic reaction and if the amount is big, it may even ignite. Perfectly dry sodium dithionite is fairly stable in contact with air, but in the long run that also will be oxidized. So, when you store it, store it in tightly sealed containers.