i need help for the three questions

A buffer solution contains 0.354M ammonium bromide and 0.235M ammonia. If 0.0270 moles of sodium hydroxide are added to 125mL of this buffer, what is the pH of the resulting solution ? (Assume that the volume does not change upon adding sodium hydroxide) A buffer solution contains 0.368M acetic acid and 0.492M potassium acetate. If 0.0320 moles of nitric acid are added to 250. mL of this buffer, what is the pH of the resulting solution ? (Assume that the volume change does not change upon adding nitric acid) A buffer solution contains 0.326M hypochlorous acid and 0.322M sodium hypochlorite . If 0.0252 moles of potassium hydroxide are added to 225mL of this buffer, what is the pH of the resulting solution ? (Assume that the volume does not change upon adding potassium hydroxide.)