What is the pH of the buffer (50.0 mL of 1.0 M acetic acid and 50.0 mL of 1.0 M sodium acetate) if pKa is 4.75? What is the pH of buffer after

What is the pH of the buffer (50.0 mL of 1.0 M acetic acid and 50.0 mL of 1.0 M sodium acetate) if pKa is 4.75?

What is the pH of buffer after addition of 2 mL of 1M NaOH?

What is the pH of buffer after addition of 2 mL of 1M HCl?