Buffers Practice Test

HCN dissociates based on the following reaction:

$HCN + H_{2}O \rightarrow CN^{-}+ H_{3}O^{+}$

The Ka for hydrogen cyanide is .

Two moles of HCN are mixed with one mole of NaCN, resulting in 1L of solution. What is the pH of the solution?

Carbonic anhydrase is an important enzyme that allows CO2 and H2O to be converted into H2CO3. In addition to allowing CO2 to be dissolved into the blood and transported to the lungs for exhalation, the products of the carbonic anhydrase reaction, H2CO3 and a related compound HCO3-, also serve to control the pH of the blood to prevent acidosis or alkalosis. The carbonic anhydrase reaction and acid-base reaction are presented below.

CO2 + H2O $\rightleftharpoons$ H2CO3

H2CO3 $\rightleftharpoons$ HCO3- + H+

HCO3- may be considered a(n)                     .