Question

Tris (tris(hydroxymethyl)aminomethane) is a weak base commonly used to make buffers. You need to prepare 1.0 L of a 0.10 M Tris buffer (i.e. total concentration of Tris and its salt = 0.10 M) of pH 7.4. You are given 500.0 mL of a 0.2 M Tris solution. What volume of 0.50 M hydrochloric acid would you need to add? pKa (Tris) = 8.06.