What's the sodium carbonate doing in the bleach?

Discussion in 'B&W: Film, Paper, Chemistry' started by walbergb, Aug 13, 2012.

  1. walbergb

    walbergb Subscriber

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    I'm into making my own bleach (potassium ferricyanide + potassium bromide) for indirect toning. I have seen recipes that include sodium carbonate (e.g., Photographers' Formulary recipe). What function does the sodium carbonate serve?
     
  2. RattyMouse

    RattyMouse Subscriber

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    Just a guess here...pH buffer?
     
  3. ajs77306

    ajs77306 Member

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  4. jm94

    jm94 Member

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    That's what I thought too, a pH buffer.