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Thread: rule of thumb

  1. #11

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    Thanks Ian, I'll have a look, but with Parodinal being fairly easy for me to make I was thinking of trying it out, those dilutions will be my starting point. Thanks!

  2. #12
    RalphLambrecht's Avatar
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    Quote Originally Posted by RidingWaves View Post
    Thanks Ian, I'll have a look, but with Parodinal being fairly easy for me to make I was thinking of trying it out, those dilutions will be my starting point. Thanks!
    can you post a formuls for parodinal? i couldn't find one.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  3. #13
    dmb
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    http://www.digitaltruth.com/data/parodinal.php - Acetaminophen (better known as paracetamol or tylenol)

  4. #14
    Ken Nadvornick's Avatar
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    I have never been able to get that sulfite ratio of 200 grams/liter to come even close to dissolving completely, even at elevated temperatures. Cutting that ratio in half (25 grams/250 ml) has always seemed to work out much better.

    Had a small (thin plastic) drinking water bottle holding an older batch. Let it sit for about a year - maybe - just to see what would happen over time. The hydroxide finally ate a hole in the side. Dripped solution, which immediately turned blackish, all over everything. What a huge mess. I shoulda' known better...



    Ken
    "They are the proof that something was there and no longer is. Like a stain. And the stillness of them is boggling. You can turn away but when you come back they’ll still be there looking at you."

    — Diane Arbus, March 15, 1971, in response to a request for a brief statement about photographs

  5. #15
    Ian Grant's Avatar
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    Quote Originally Posted by Ken Nadvornick View Post
    I have never been able to get that sulfite ratio of 200 grams/liter to come even close to dissolving completely, even at elevated temperatures. Cutting that ratio in half (25 grams/250 ml) has always seemed to work out much better.

    Had a small (thin plastic) drinking water bottle holding an older batch. Let it sit for about a year - maybe - just to see what would happen over time. The hydroxide finally ate a hole in the side. Dripped solution, which immediately turned blackish, all over everything. What a huge mess. I shoulda' known better...



    Ken
    Concentrated solutions of Sulphite are best made from Sodium or Potassium Metabisulphite and Hydroxide.

    Ian

  6. #16
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    Sodium sulfite
    From Wikipedia, the free encyclopedia
    Sodium sulfite


    anhydrous

    hydrate
    IUPAC name[hide]
    Sodium sulfite
    Other names[hide]
    Hypo clear (photography)
    E221
    Identifiers
    CAS number 7757-83-7
    PubChem 24437
    ChemSpider 22845
    UNII VTK01UQK3G
    RTECS number WE2150000
    Jmol-3D images Image 1
    SMILES
    [show]
    InChI
    [show]
    Properties
    Molecular formula Na2SO3
    Molar mass 126.043 g/mol
    Appearance white solid
    Density 2.633 g/cm3 (anhydrous)
    1.561 g/cm3 (heptahydrate)
    Melting point
    33.4 °C (dehydration of heptahydrate)
    500 °C (anhydrous)
    Boiling point
    Decomposes(separate (substances) into constituent elements)
    Solubility in water 678 g/L (18 °C, heptahydrate)
    according to wikepedia, the solubility of sodium sulfite in 18cwater is above 600g/l
    Sodium sulfite
    From Wikipedia, the free encyclopedia
    Sodium sulfite


    anhydrous

    hydrate
    IUPAC name[hide]
    Sodium sulfite
    Other names[hide]
    Hypo clear (photography)
    E221
    Identifiers
    CAS number 7757-83-7
    PubChem 24437
    ChemSpider 22845
    UNII VTK01UQK3G
    RTECS number WE2150000
    Jmol-3D images Image 1
    SMILES
    [show]
    InChI
    [show]
    Properties
    Molecular formula Na2SO3
    Molar mass 126.043 g/mol
    Appearance white solid
    Density 2.633 g/cm3 (anhydrous)
    1.561 g/cm3 (heptahydrate)
    Melting point
    33.4 °C (dehydration of heptahydrate)
    500 °C (anhydrous)
    Boiling point
    Decomposes(separate (substances) into constituent elements)
    Solubility in water 678 g/L (18 °C, heptahydrate)
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

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