How does temperature and pH affect the solubility of p-nitrophenol?

[sweetburntlip]

Hi!

Can anyone inform me on the solubility of p-nitrophenol? I want to make 1 molar solution of the substance, which is 0.0139g/100 ul (MW is 139). Unfortunately, my solution seems to be supersaturated as the solute is still visible.

Do I need to do anything to my solution to make it soluble?

At Wikipedia, the pKa of p-nitrophenol is 7.08 at 20∘C.

 

[Borek]

Wikipedia lists solubility as 11.6 g/L (20 °C), almost 10 times lower than you need. Heating up and increasing pH should increase the solubility, whether it will get high enough - hard to say. Question is - does hot alkaline solution fit your needs?

 

[sweetburntlip]

Thanks for your reply.

I diluted it instead to 100ml to make 10mM solution as it was impossible to dilute at 1M.

 

[fafali]

I'm studying adsorption kinetics of PNP, need to prepare complete soluble of PNP solution, I do add the solid of PNP into deionized distilled water then heating up to 80deg C and stirring at 1000rpm for few hours, but still exists very tiny solid/particle. Is it considered completely soluble?

 

[pmsrw3]

I think you'll be able to dissolve it if you add excess base.

 

[pmsrw3]

Question is - does hot alkaline solution fit your needs?

I'm guessing this is s stock solution that will be diluted for final use. (I can't imagine why anyone would directly use a 1M solution.) If so, and as long as it will be diluted into buffer, some excess base shouldn't be a big problem.