Quote Originally Posted by gainer
A saturated solution of potassium paraminophenolate should have a certain pH. The concentration of sulfite may have some effect on how concentrated a saturated solution can be, but I cannot see how precipitated p-aminophenol can affect pH. It is not ionized, is it?
Patrick - if something is dropping out of solution, it will be removing ions from the solution. This can affect the pH of that solution (or the buffering capacity) depending on what it is that has dropped out.

So it is not the unionized material sitting on the bottom of the vat that affects the solution pH, but it is the ions that were removed from solution that can affect the pH.

Kirk - www.keyesphoto.com