A 200 mL sample of buffer of pH = 4.00 is required for a biochemical experiment. You have solutions of 0.100 M benzoic acid (C6H5COOH, MM = 123.1 g.mor", pka = 4.17) and 0.200 M sodium benzoate (C6H5COONa, MM = 145.1 g.mor). (a) What is the [base): (acid] for this buffer? (1 pt) (b) Describe how you would prepare this buffer. Hint: we don't know the total concentration of the acid and its conjugate base, but we do know the total volume. How can you use this to your advantage? (3 pts)