Parodinal Na+K Equation question

Discussion in 'B&W: Film, Paper, Chemistry' started by Herzeleid, Jan 2, 2018.

  1. Herzeleid

    Herzeleid Member
    Ads Enabled

    Messages:
    328
    Joined:
    Oct 31, 2008
    Location:
    Ankara/Turkey
    Shooter:
    Multi Format
    I have decided mix some Parodinal for myself, since it was extremely easy to prepare. This is the first time I made a film/paper developer so I don't have experience with developer chemistry.

    First, I prepared a quite simple potassium variation, Parodinal-K
    Potassium Hydroxide.......................28,3 gr
    Paracetamol........... 15gr (Not tablets, from powdered paracetamol)
    Sodium sulfite........ 50 gr
    KBr........................2.5 gr
    Water to make.....................250ml

    I dissolved sodium sulfite in a beaker, in another beaker I mixed KOH. I added Paracetamol into KOH, slight color change happened showing hydrolysis and probably some oxidation so I started adding sulfite solution into it. Added the rest of the chemicals and adjusted the volume. I had a pink colored super clear solution as expected. I have waited two days and it worked as expected, and color is lot darker now.

    Next I tried a variation today. Prepared with metabisulfite since it was easier to dissolve and with double replacement I would have potassium sulfite in theory.

    Parodinal-NaK
    Potassium Hydroxide.......................20.4 gr
    Sodium Meta-bisulfite........ 15.4 gr
    Paracetamol........... 6gr
    KBr........................1 gr
    Water to make.....................100ml

    Metabisulfite is fist dissolved and then I gradually added KOH in cold water to keep the solution from overheating, the solution became clear then I added paracetamol and KBr adjusted the volume. It is clear as water no hint of color, I will have to wait to a few days see any change
    Well I can balance the metabisulfite and hydroxide reaction equation in two ways, which puzzles me

    Na2S2O5 +2KOH = K2SO3 + NaOH +H2O
    or
    Na2S2O5 +2KOH = K2SO3 + Na2SO3 +H2O

    I see two possibilities developer has sodium and potassium sulfite and excess potassium hydroxide, or it has potassium sulfite with sodium and potassium hydroxide.
    In the end I will have a developer with potassium salt of aminophenol or one with both Na and K aminophenol salts in the developer.

    It is possibly a simple chemistry thing but care to enlighten me and may be theorize the effectiveness or its uselessness.

    Regards
     
  2. Rudeofus

    Rudeofus Subscriber
    Ads Enabled

    Messages:
    3,582
    Joined:
    Aug 13, 2009
    Shooter:
    Medium Format
    As soon as everything is in aqueous solution, all ions are more or less dissociated, i.e. you don't have KOH or Na2S2O5 or whatever in solution, you have K+ and Na+ and OH- and SO3-- and HSO3- and so on, depending on pH. At the expected very high pH of your Parodinal mix, you should expect a mix of K+, Na+, SO3-- and OH- on the right side of your equation.
     
  3. trendland

    trendland Member
    Ads Enabled

    Messages:
    2,632
    Joined:
    Mar 16, 2012
    Shooter:
    Medium Format
    Yes - I can imagine the doubts you may have now. ....:cry::cry::cry:....!
    If I understand you correct (hope so) the question now is - damned what will happen next ...:D...am I right or am I right.

    I should tell you ? No - that should be your task - but I will give you a hind -

    Procede with development next.
    Ok therefore you need a film ?
    What about Ilford Fp4 ?

    Seriously - your formulation looks pretty good. The procedure/workflow is just fine - from my mind.

    It will nothing happen in concern of fire/explosions - nice to know.
    Perhaps others have corrections from formulation - but this might be variant from own experience.
    Not to forget variants from history.
    I would let it so as you have shown.

    I don't linke rodinal so much - but this should not be your case.

    So pls. Go ahead - Go ahead - Go ahead.

    with regards

    (Amstrong was in same situation - as he
    realized - all systems at go 1min. minus 12 (sec.).....:cry::cry::cry:)
     
  4. trendland

    trendland Member
    Ads Enabled

    Messages:
    2,632
    Joined:
    Mar 16, 2012
    Shooter:
    Medium Format
    Aha I see - you are douptfull about Na3So2 thats a difference. ...:D:happy:...
    I remember a simular case - can't say of being also Na3So2 - it was from a big:laugh: list of chemicals to be needed.
    But in my case both were ok.

    with regards
     
  5. trendland

    trendland Member
    Ads Enabled

    Messages:
    2,632
    Joined:
    Mar 16, 2012
    Shooter:
    Medium Format
    Ok - I had it in mind. If it would be my developing action I would make my choise indeed on NaOh but Rodeofus mentioned it has an impact on the ph but that is to be solved from mesurement (ph meter/ph stripes) via concentration/amound of it.
    But be aware - this chemical can indeed explode if you make everything not as described from your source.
    But you have solved it so everything has gone good - yeah?

    with regards
     
  6. OP
    OP
    Herzeleid

    Herzeleid Member
    Ads Enabled

    Messages:
    328
    Joined:
    Oct 31, 2008
    Location:
    Ankara/Turkey
    Shooter:
    Multi Format
    I haven't thought about it this way, you have a point. So I guess sodium and potassium salts of aminophenol should form and dissolve in the mixture.
    Both developers should be identical in that case.
     
  7. OP
    OP
    Herzeleid

    Herzeleid Member
    Ads Enabled

    Messages:
    328
    Joined:
    Oct 31, 2008
    Location:
    Ankara/Turkey
    Shooter:
    Multi Format
    I will have to test the new developer eventually, but I feel like that both developers will act the same.
    I am very cautious when mixing hydroxides, so no worries there :smile:

    I already made a test with an expired Delta400 1+25 and it worked exactly as rodinal. Base fog is 0.35, Dmax is around 1.75 (average reading of 3mm circle).
    It really works as expected. I am impressed with the formula.
     
  8. Rudeofus

    Rudeofus Subscriber
    Ads Enabled

    Messages:
    3,582
    Joined:
    Aug 13, 2009
    Shooter:
    Medium Format
    As soon as you have an aqueous solution, it doesn't matter which ingredient brought in which ion, you will end up with the sum of all ions as separately hydrated units. A cluster of ions will only form in case of complexation (e.g. Fe+++ + 6 CN- <---> Fe(CN)6--- or Ag+ + 2 S2O3-- <---> Ag(S2O3)2---), or if one of the salts precipitates from solution (Ag+ + Br- <---> AgBr). Since neither reaction is relevant to Parodinal, all ions will stay separate in your case.
     
  9. Alan Johnson

    Alan Johnson Subscriber

    Messages:
    1,979
    Joined:
    Nov 16, 2004
    The first formula you posted, PaRodinal K is the standard Parodinal formula with NaOH replaced by KOH and it came out clear, presumably with no crystals.
    I haven't done the calculation for the second formula, is that accurate to the standard formula with some K instead of Na ,.ie contains the same stoichometric proportopns of OH, acetaminophen and sulfite/?
     
  10. OP
    OP
    Herzeleid

    Herzeleid Member
    Ads Enabled

    Messages:
    328
    Joined:
    Oct 31, 2008
    Location:
    Ankara/Turkey
    Shooter:
    Multi Format
    Yes, the first formula is Donald Quall's Parodinal formula replace NaOH with molar equivalent of KOH. Second developer formula is also the same. May be very little difference in KOH amount to ensure all metabisulfite is reacted.
    We can say they are stoichometrically identical.
     
  11. OP
    OP
    Herzeleid

    Herzeleid Member
    Ads Enabled

    Messages:
    328
    Joined:
    Oct 31, 2008
    Location:
    Ankara/Turkey
    Shooter:
    Multi Format
    Oh, and both formulas are very clear and I haven't observed any tendency to precipitate yet. No crystallization at the moment.
     
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies. If you have a Photrio account, please log in (and select 'stay logged in') to prevent recurrence of this notice.