CHM 121 Lecture Notes - Lecture 5: Buffer Solution, Equivalence Point, Inflection Point

• School: University of Miami
• Department: Chemistry
• Course: CHM 121
• Professor: Leslie Knecht

Document Summary

Buffers are solutions that resist changes in ph when an acid or base is added. There is a limit to what they can do, and eventually the ph changes. Buffers are made by mixing a solution of a weak acid with a solution of soluble salt of its conjugate base anion. Blood has a mixture of h2co3 and hco3. Na does(cid:374)"t (cid:373)atter, spe(cid:272)tator: common ion effect. Buffers exploit the common ion effect that shifts an equilibrium due to addition of a salt of the (cid:272)o(cid:374)jugate a(cid:272)id or (cid:271)ase. The presence of a common ion suppresses the ionization of a weak acid or a weak base. Buffers resist change in ph when acid or base is added, but their ph does change. Calculating the new ph requires breaking the problem into two parts. Added acid reacts with the a to make more ha. Added base reacts with the ha to make more a .