posted by shanice .
What is the pH of the solution obtained by diluting 500 mL of 0.0200 M NH3 (aq) to 1.000 L ?
NH3 + HOH ==> NH4^+ + OH^-
Kb = (NH4^+)(OH^-)/(NH3)
This problem is like the CH3NH2 problem I worked for you. The only difference is that it is a diluted solution. The new concn of NH3 is 0.0200 M x (500/1000) = ??