Hello all, I had chemistry a long time ago, but now I am very rusty at it so I am hoping you can get me started with this problem I have; A particular solution of ammonia (Kb = 1.8 x 10-5) has a pH of 8.3. What is the concentration of ammonia in this solution? Is it the concentration of NH3 I have to find? I know I can find [OH-] since I know the pH, but what does the final equation look like? Something like [tex]Kb=[OH-][NH4+]/[NH3][/tex]? Thank you for any help!