Solubility‪‪‬‪‪‬‪‪‬‪‪‬ ‪‪‬‪‪‬‪‪‬‪‪‬ ‪‪‬‪‪‬‪‪‬‪‪‬?

Gout is an extremely painful, sometimes debilitating, disease caused by an error of nucleic acid metabolism or excretion that leads to a build up of uric acid in body fluids, which is deposited as slightly soluble sodium urate (C5H3N4O3Na) in the soft tissue of joints. If the extraceullar [Na+] in humans is 0.15 M and the solubility in water of sodium urate is 0.085 g/100 mL, what is the minimum urate ion concentration [UR-] that will cause a deposit of sodium urate?