How to mix platinum toner?

[menglert]

I want to mix a toner for Kallitypes, but want to be clear I have the right solutions. This is the toner formula I would like to use.

Citric acid 5g
Potassium chloroplatinite 20% solution 5ml
Water 1000ml

What I am questioning, is the 20% solution, and how to mix this. Is it 10ml water plus 2g of Potassium chloroplatinite( 2g/10ml=20%)?

Another formula I found uses this:

Citric acid 5g
Potassium chloroplatinite 0.5g
Sodium chloride 5g
Water 1000ml

I don't have Sodium chloride, can I use this toner formula without it?

Thanks for your help.

-Martin

 

[scootermm]

Martin...
Just a week ago there was a long discussion on this. Check about 3/4 of the way down the Alt Process forum.


the thread is here.
(there was a url link here which no longer exists)

 

[menglert]

I've already read the other forum about this topic, and it didn't answer the question.

The chloroplatinite is in powder form. I have 2 grams of it. I have to make the solution by adding only water I assume. In the previous thread they talk about using 100ml of water, but doesn't this give you a 2% solution (2g/100ml= 2%)?

Wouldn't I have to mix 2 grams of chloroplatinite with 10ml of water to get a 20% solution?

 

[Shinnya]

Yes,

You will need 10 ml, not 100 ml, to make 20% solution.

Good luck.

Warmly,
Tsuyoshi

I've already read the other forum about this topic, and it didn't answer the question.

The chloroplatinite is in powder form. I have 2 grams of it. I have to make the solution by adding only water I assume. In the previous thread they talk about using 100ml of water, but doesn't this give you a 2% solution (2g/100ml= 2%)?

Wouldn't I have to mix 2 grams of chloroplatinite with 10ml of water to get a 20% solution?

 

[menglert]

Thanks for helping with my question.

Regards,
Martin

 

[Shinnya]

Martin,

By the way, Pt solution is very close to saturation. Once in a while, there may be some precipitate. You will need to warm up the solution to let the salt go into the solution again.

Warmly,
Tsuyoshi

 

[Claire Senft]

If you have table salt, you have sodium chloride.

 

[GregT.]

What I am questioning, is the 20% solution, and how to mix this. Is it 10ml water plus 2g of Potassium chloroplatinite( 2g/10ml=20%)?

A percent solution is not simply a matter of adding a certain volume of liquid to the weight of a material. A percent solution is the concentration of a soluble material (solute) in parts per hundred of the total solution.

To make a percent solution of anything, weigh the desired percentage amount of your soluble material and place it into your beaker or graduate. Slowly add your solvent while dissolving the soluble material and bring the total volume up to 100ml.

In other words, to make 100ml of a 20% potassium chloroplatinite solution, weigh 20g of potassium chloroplatinite, dump it into your graduate and add water while dissolving the potassium chloroplatinite bringing the total volume up to 100ml.

Weighing 2g and adding water to bring the total volume up to 10ml is what you're looking for.

 

[Photo Engineer]

If you have table salt, you have sodium chloride.

If you have standard table salt, you have a mixture of sodium chloride, sodium or potassium iodide and silicate based dessicants along with a host of minor fillers such as starch grains.

PE

 

[menglert]

Thanks for all your replies and suggestions. I'll make up the toner this week.

Regards,
Martin

 

[carioca]

I want to mix a toner for Kallitypes, but want to be clear I have the right solutions. This is the toner formula I would like to use.

Citric acid 5g
Potassium chloroplatinite 20% solution 5ml
Water 1000ml

What I am questioning, is the 20% solution, and how to mix this. Is it 10ml water plus 2g of Potassium chloroplatinite( 2g/10ml=20%)?

Old post, but same uncertainty...
Making a platinum toner from solids with the above formula, would that be:

Citric acid 5g
Potassium chloroplatinite 1g (solid)
Water to make 1L - resulting in a final 0.1% Pt solution

Checking the internet chemical resource pages and Wiki regarding the typical 20% concentration for Platinum printing sold on the market,
how is it possible to get a 20% solution if Potassium Chloroplatinite is barely soluble at 1g/100ml H2O (@16°C) or the most 6g/100ml H2O at boiling temp...??

Sidney

 

[nmp]

Old post, but same uncertainty...
Making a platinum toner from solids with the above formula, would that be:

Citric acid 5g
Potassium chloroplatinite 1g (solid)
Water to make 1L - resulting in a final 0.1% Pt solution

Checking the internet chemical resource pages and Wiki regarding the typical 20% concentration for Platinum printing sold on the market,
how is it possible to get a 20% solution if Potassium Chloroplatinite is barely soluble at 1g/100ml H2O (@16°C) or the most 6g/100ml H2O at boiling temp...??

Sidney

Your translation from 5 ml @ 20% solution = 1 gm of solid is correct.

The question about the solubility is interesting - could it be that wiki is wrong on this one. Never made my own solution so never looked up the solubility before. Checked a couple of books I have but none cautioned about low solubility of the potassium chloroplatinate when listing the formula to make the 20% solution. Mike Ware mentions saturation at 0.43 molar which by my calculations comes to about 18% w/v. May be someone can chime in who has made 20% solution from scratch.

In any case, as long as you are making the toning solution which is considerably below the wiki solubility of less than 1%, you are fine.

:Niranjan.

 

[NedL]

I'm watching the thread with interest too... I have a little bottle of 20% solution, so clearly it's possible, but have found several references for potassium tetrachloroplatiate(II) listing solubility near 1g/100ml at room temperature.

 

[carioca]

Your translation from 5 ml @ 20% solution = 1 gm of solid is correct.

The question about the solubility is interesting - could it be that wiki is wrong on this one. Never made my own solution so never looked up the solubility before. Checked a couple of books I have but none cautioned about low solubility of the potassium chloroplatinate when listing the formula to make the 20% solution. Mike Ware mentions saturation at 0.43 molar which by my calculations comes to about 18% w/v. May be someone can chime in who has made 20% solution from scratch.
:Niranjan.

Thanks for confirming the right quantity of my mix
Regarding the solubility issue, all chemical property pages I have come across, mention 1g/100ml. Most likely, people just copy (the wrong information), so the error ends up everywhere.

I have found a copy of Dick Arentz' Pt/Pd book and he mixes 10g in 50ml of warm water, with the following side note: "Technically, this is not a 20% solution; however, it has been listed as such in the literature for over 100 years - and it works".

Voilà, mystery solved.
Sidney

 

[fdonadio]

Sorry if I am adding noise. I have zero experience with palladium.

I see the toner formula calls for 5g citric acid, which will affect the pH of the mixture considerably. Maybe the acidity will help dissolve the potassium chloroplatinate?

 

[carioca]

I see the toner formula calls for 5g citric acid, which will affect the pH of the mixture considerably. Maybe the acidity will help dissolve the potassium chloroplatinate?

The initial formula calls for a 20% Pt solution, that is prior to adding the citric acid.
I did some research in old photographic literature and Pt does seem to be quite soluble in water, contrary to what most internet pages claim...

As :Niranjan mentioned, it gets to saturation at around 18%+. It is called a 20% concentration historically, even though it is not a true 20%.

Sidney

 

[fdonadio]

Well, if it works, I guess it’s all right.!

 

[Rolleiflexible]

Another question before closing the book on this conversation:

Why make this a two-step process? Is there any reason not simply to dump the gram of chloroplatinite and the 5mg of citric acid into a liter of water? What is the point of making up a 5% solution of chloroplatinite and water first, and then putting that into the liter of water?

What am I missing?

 

[nmp]

Another question before closing the book on this conversation:

Why make this a two-step process? Is there any reason not simply to dump the gram of chloroplatinite and the 5mg of citric acid into a liter of water? What is the point of making up a 5% solution of chloroplatinite and water first, and then putting that into the liter of water?

What am I missing?

You mean 20% right? My guess is it is because most people buy or have at hand the solution for Pt/Pd printing, that is 20%.

:Niranjan.

 

[Rolleiflexible]

You mean 20% right? My guess is it is because most people buy or have at hand the solution for Pt/Pd printing, that is 20%.

:Niranjan.

Yes, I meant 20 percent, sorry. I have the solid on hand. A lot of the preceding discussion is about the difficulty of dissolving the solid into a 20 percent solution. It makes me wonder: Why bother?

 

[nmp]

Yes, I meant 20 percent, sorry. I have the solid on hand. A lot of the preceding discussion is about the difficulty of dissolving the solid into a 20 percent solution. It makes me wonder: Why bother?

Looking thru the thread again, it looks like it went on a side track about solubility. You are right, if you are starting out from the powdered form, there is no reason to worry about how to get 20% solids in solution.

:Niranjan.

 

[Jurgen Estanislao]

Chiming in on this thread.

I think it can get confusing even to do those doing pure Pt prints.

Working solution for Pt Sol. 3 for example is at 20%.

In powder form, instructions from from the Bostick & Sullivan Website and even Dick Arentz' book would say dissolve 1 gram of Pt powder to 5ml of distilled water (Arentz has the same formula where you mix 10g of Pt powder to 50ml of distilled water).

If you follow this, 5grams of Pt Powder will give you approx 30ml of working solution, 10grams at 60ml, 20grams at 120ml, and so on, this comes out at 16% working solution not taking into account any changes on the chemistry (not a chemist here).

Arentz' book does note that this formula is not a true 20% solution but it works.

Then when you check Bostick's site for working solutions, they have a graduated cylinder on the site showing a 25ml bottle has 25ml exactly, assuming it means this doesn't have 5grams of Pt.

So here I am with 20grams if Pt to make Pt Sol. 3 and I am in a conundrum if I should top it up to make 100ml or add 100ml to make approx 120ml.

 

[koraks]

If you follow this, 5grams of Pt Powder will give you approx 30ml of working solution

I don't think so. If you dissolve 1g of a powder into 5ml water, the total volume will be slightly over 5ml but not much, and certainly not 6ml. Two reasons for this:
1: Pt has a higher density than water, so 1g of a Pt salt will never be 1ml to begin with
2: When dissolving a powder into a liquid, the volume of the solution tends to be smaller than that of its constituents.

Adding 1g chloroplatinate (for instance) to 5g of water will yield a solution of maybe 19% or so - not quite 20%, but not far off.

The correct way of making a 20% w/v solution would be to start with a smaller volume (e.g. 3ml), dissolve the powder, make up to the final volume. Evidently this doesn't work very well for very small volumes, so the 'add 1g to 5ml' is a practical compromise that accomplishes something that's in practice more than good enough - especially if the same approach is taken consistently.

 

[Jurgen Estanislao]

I don't think so. If you dissolve 1g of a powder into 5ml water, the total volume will be slightly over 5ml but not much, and certainly not 6ml. Two reasons for this:
1: Pt has a higher density than water, so 1g of a Pt salt will never be 1ml to begin with
2: When dissolving a powder into a liquid, the volume of the solution tends to be smaller than that of its constituents.

Adding 1g chloroplatinate (for instance) to 5g of water will yield a solution of maybe 19% or so - not quite 20%, but not far off.

The correct way of making a 20% w/v solution would be to start with a smaller volume (e.g. 3ml), dissolve the powder, make up to the final volume. Evidently this doesn't work very well for very small volumes, so the 'add 1g to 5ml' is a practical compromise that accomplishes something that's in practice more than good enough - especially if the same approach is taken consistently.

Thanks for clarifying. I only meant to simplify or make the point that it will never be exact in milliliters/will always be more than 25ml for 5g for example.

On that note, you recommend mixing 20g to 100ml distilled water? Or Add distilled water to 20g to make 100ml? Or it doesn't matter as much?

 

[fgorga]

The most accurate way to make any solution is to put about 75% of the desired final volume of the solvent (water in this case) in a container and then add the desired amount of solid. When the solid is dissolved, add more solvent to reach the desired volume.

The more concentrated the solution the more important it is to flow the above procedure if you want an accurate concentration. For dilute solutions, say 5% (w/v) or less, one can probably get away with just adding the solid to the final desired volume. The difference in final volume (and hence concentration) is minimal at low concentrations.

For making small volumes of solution using expensive solids, one can probably get away with just adding the solid to the liquid.

In all cases consistency is the key. Make each batch of a solution the same way each time you make it. That way any minor deviations will be the same and the solution will give consistent results over time.

Adding the solid to the liquid is generally preferred as you avoid clumping of the solid into a large mass that is slow to dissolve.