A buffer solution is prepared by mixing 50.0 mL of 0.300 M NH3 with 50.0 mL of 0.300 M NH4Cl. the pKb is 4.74.

NH3 + H2O ? NH4+ + OH -

Calculate the [NH3] and [H4Cl] in the buffer solution. Calculate the pH of the buffer solution.

7.50 mL of 0.125 M HCl is added to the 100.0 mL of the buffer solution. Calculate the new [NH3] and [NH4Cl] for the buffer solution. Calculate the new pH of the solution.

7.50 mL of 0.125 M NaOH is added to the 100.0 mL of the buffer solution. Calculate the new [NH3] and [NH4Cl] for the buffer solution. Calculate the new pH of the solution.