Sodium sulfite desiccated" or "Sodium sulfite anhydrous

[OMU]

Hello,
I would like to play with some a amidoll paper developer.

There are different recepies;
unblinkingeye.com/Articles/Amidol/amidol.html

Some with "Sodium sulfite desiccated" and some with "Sodium sulfite anhydrous.

I hope anyone can tell me the differense about those cemicals. I have the anhydrous, can I use it instead of the desiccated?

Thanks

 

[Ian Grant]

They are the same - both mean no water, the other form which really only appears in US publications is Crystalline (cryst) which is the heptahydrate form.

Ian

 

[OMU]

Thanks Ian,
Can I use the same weight for both of them, (sorry for my English )

 

[jochen]

Hello,
Sodiumsulfite cryst. has 7 moles of crystal water and the molecular weight of 252, the anhydrous form has a molecular weight of 126. So you can take either 1 gr. Sodiumsulfite sicc. or 2 gr. of the crystalline form. The anhydrous form is much more stable at air, so the crystalline salt is virtually not available on the market. Sicc. is Latin and means "siccum" = dry.

 

[PhotoJim]

"Dessicated", when it comes to chemicals, is an obsolete term that has now been replaced by "anhydrous". Both mean the same thing - without water molecules.

 

[Ian Grant]

Thanks Ian,
Can I use the same weight for both of them, (sorry for my English )

Yes, they are the same chemical just a different term meaning the same thing.

Ian