Parodinal Na+K Equation question

Herzeleid said:

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

Click to expand...

Rudeofus said:

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.

Click to expand...

trendland said:

Yes - I can imagine the doubts you may have now. ........!
If I understand you correct (hope so) the question now is - damned what will happen next ......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.).....)

Click to expand...

Alan Johnson said:

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/?

Click to expand...