Ferric oxalate formula please

[sly]

Could anyone who mixes ferric oxalate from powder for pt/pd please let me know your formula - how many grams to how much water? do you add oxalic acid? do you heat it? stir it? shake it? I've been trying to make some and can't get it to dissolve. I'd trying to figure out if I've got the proportions all wrong, or just spent my money on useless chemicals.

Thanks in advance

 

[Andrew O'Neill]

I mix a 20% solution. I start with 75ml of distilled water at around 65 Celcius. Add 20g ferric oxalate and stir in. I mix in a brown bottle by shaking violently. Then I add more hot distilled water to make 100ml and give a good shake. Bostick and Sullivan's ferric oxalate goes in easily. The stuff from JDphotochem takes a very long time to go in, but it will eventually.

 

[sly]

The formula I've been using is closer to 30%. No wonder I can't get it to dissolve. I'll decant what I've got and see how it works. The next time I'll use your formula.

 

[Jim Noel]

If you let it sit overnight, all that can be dissolved will do so. If any sediment left, decant.