i need ii and iii, i am completely lost

(ii) Preparation of 100 ml of 0.15M acetate buffer, pH 4.1, using 1M acetic acid and IM NaOH. (iii) What will be the pH of buffer (ii) if 5 ml of 1M NaOH is added to that buffer Find out the pH through calculations Acetate buffer 3.8-5.9 pH 4.76 pka