buffer solution containing 0.15 mole of acetic acid (CH₃COOH) and 0.125 mole of sodium acetate (CH₃COONa) (Ka=1.86x10^-5)

1) How will the concentration of hydrogen ions and the pH of this solution change if 3 cm³ of a 0.25 molar NaOH solution is added to it.

2) How will the concentration of hydrogen ions in 1 dm³ of 0.05M H₂SO₄ change if we add to it successively 1 cm³ of 1 molar HCl and 3 cm³ of 1 molar NaOH.