Question

1. Given 1 L of 0.05 M sodium bicine (conjugate base of the buffer), how much 0.1 N HCl must be added to make a bicine solution of pH 7.5? What is the molarity of bicine in the final buffer? The pK_a is 8.26.

2. You take 2.38 g of HEPES in the acid form and bring the volume up to 100 mL with water. We will call this solution A. You then add 3 mL of 1 M NaOH to make solution B. Finally you add 7 more mL of 1 M NaOH to make solution C. What are the pH values of the 3 solutions? (The molecular weight of HEPES is 238. 3 g/mol and the pK_a is 7.55; HEPES is a weak acid commonly used for biological buffers.