Quote Originally Posted by Photo Engineer View Post
According to my textbooks, the dihydrate can be rapidly oxidized to the sulfate if not tightly capped. It therefore appears to be less soluable as Potassium Sulfate is less soluable.

Might be a thought to consider.

Also, 50% by weight is an incomplete spec in this case. Due to the high solubility of some items the full spec of wt/vol or wt/wt must be used for accuracy.

PE
Ron, dad blamit, I was not saying we need a 50% solution for the Rodinal expedient. I was saying that if I could not get 100 grams of what I have to dissolve in 100 grams of water, there is something wrong with what I have in the container labelled "Potassium Sulfite." A 28% wt/wt solution would be just ducky, but I couldn't even get that.