0.002 moles of NH3 are added to 1 liter of pure water. The pKa of NH4 + , is 9.25. Calculate the final pH, [NH4 +], and [NH3] in the solution.

Hint: You will need to use a charge balance expression (concentration of positive charge in solution = concentration of negative charge in solution) plus equilibrium and mass balance expressions. You can also assume that the concentration of [H+] is negligible compared to other species in solution because NH3 is a base that will raise the pH of water that is initially at pH 7.0