Exhibit 2B
Contains Information on the PK's of Some Common

Multiple Choice

Exhibit 2B
Contains information on the pK's of some common buffers.
$\begin{array}{llrc}\text { Buffer } & \mathbf{p K} 1 & \mathbf{p K 2} & \mathbf{p K} 3 \\\hline \text { Acetate } & 4.75 & & \\\text { Ammonia } & 9.25 & & \\\text { Carbonic acid } & 6.37 & 10.20 & \\\text { Citric acid } & 3.09 & 4.75 & 5.41 \\\text { Formic Acid } & 3.75 & & \\\text { Phosphoric acid } & 2.14 & 7.20 & 12.4 \\\text { Pyruvic acid } & 2.50 & & \\\text { Tris } & 8.3 & &\end{array}$

-Refer to Exhibit 2B. An ammonium buffer would work well at this pH:

A) 5.6
B) 7.0
C) 9.0
D) 11.0
E) None of these