Question

pH buffer preparation: You have a 1L volumetric flask, 10. M HCl, solid NaOH, nanopure water, and a container of the weak base sodium bisulfide (NaSH, pKb = 7.0, – where in water this “salt” dissociates into Na+ and SH- ions).  

a. (6 points) Describe your process for producing a pH buffer with 0.1M of both the weak acid and its conjugate base. Make sure to include the exact mass or volume of every single substance you utilize to create this pH buffer solution in your process.

b. (4 points) Calculate the buffer capacity of this pH buffer you created in part-a; where the buffer capacity is considered as the number of moles of strong acid or base added to the system (assume no effect on the volume) that would lead to a change in the buffered system pH of +/- 1.0 . Report your answer with 2 significant digits.  

c. (4 points) Returning to the buffer you created in part-a, which buffers the system to a pH=7.0; how much strong base (in moles, assuming no change in the total volume of the system) would have to be added to the system for the pH to become equal to 7.3. Report your answer with 2 significant digits.  

Answer 1