Biochemistry homework

1. ) how many grams of sodium succinate (MW=140 g/mol) and disodium succinate (MW 162 g/mol) must be added to 1 L of water to produce a solution with pH 6.5 and a total solute concentration of 40 mM? The pKa is 5.64.

2.) You are hired in a lab and are asked to make a buffer of a pH of 10.2.

 a. What acid/ conjugate base pair is best for this solution? Why?

b. Calculate the amount (in grams) of the acid/ conjugate base you should combine to get 2L of 0.5 M solution.

3.) Buffers are important physiological compounds that resist change in pH.

a). Calculate the pH of the buffer system that is 0.75 M benzoic acid and 0.25 M benzoate if pKa=4.2

b). Calculate the number of moles of benzoic acid that are required to make a liter of 0.25 M buffer solution at the pH calculated in part a