sodium acetate as a developer anhydrous or trihydrate?

Discussion in 'Alternative Processes' started by macclad, May 21, 2010.

  1. macclad

    macclad Member

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    Hey guys

    I want to use sodium acetate as a developer for kallitypes. I live in the uk and the only cheap sodium acetate i can get is the trihydrate stuff. what is the difference between the anhydrous and the trihydrate sodium acetate? and can i use the trihydrate?

    thanks

    matt
     
  2. Loris Medici

    Loris Medici Member

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    Matt, just the molecular mass differs between them; anhydrous = 82g / mole, trihydrate = 136g / mole.

    If your formula calls 350g "anhydrous" sodium acetate per liter but you have trihydrate on hands, then:

    136g (trihydrate) / 82 g (anhydrous) * 350g (anhydrous equiv.) = use 580g (trihydrate equiv.)

    Hope this helps,
    Loris.
     
  3. Athiril

    Athiril Subscriber

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    Trihydrate is hydrated.

    I imagine you would need to use more of it in a recipe that asks for anhydronous as above.

    You should be able to heat it up to dehydrate it, though unecessary, you can also make it with bicarb + vinegar (trihydrate).

    Silverprint sells sodium acetate in the anhydronous form for about 15 pounds if you really want it.
     
  4. macclad

    macclad Member

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    Thanks for that info guys. I had seen the anhydrous stuff on the silverprint website but compared to the trihydrate on eBay it's very expensive so I shall give it a go with the trihydrate and report back.

    Many thanks