Properties of Water

calculate the pKa of a propinoic acid solution, given that when the concentration of propionic acid is .1 M and the propionate ion concentration is .43 M, the pH is 5.5.

4.87

the large dipole moment of water is due to

1. the electronegativity of the Oxygen atom of water 2. waters bent geometry 3. the polarity of the O-H bond

calculate the pKa of formic acid, given that when the concentration of formic acid is .1 M and the formate ion concentration is .018M, the pH is 3.01

3.75

what is the pH of 10^-4 M HCl?

4

in a typical eukaryotic cell the pH is usually around 7.4. What is the hydrogen ion concentration in a typical eukaryotic cell?

4 X 10^-8 M

the extensive h-bonding network of liquid water molecules around a nonpolar molecule is called

a clathrate

you want to study an enzyme reaction at pH 4.0. Which of the following weak acids would make the best buffer solution for this pH based on the given Ka values? a. Phosphoric Acid Ka = 7.3 X 10^-3 b. Lactic Acid Ka = 1.4 X 10^-4 c. Acetic acid Ka = 1.7 X 10^-5 d. H2PO4 - Ka = 6.3 X 10^-8 e. Bicarbonate Ka = 6.3 X 10^-11

b. lactic acid Ka = 1.4 X 10^-4

water derives all its special properties from its:

polarity and hydrogen-bonding capacity

when the pH equals the pKa of a weak acid, then:

the concentrations of the weak acid and its conjugate base are equal

a clathrate is

the extensive hydrogen-bonding network of liquid water molecules around a nonpolar molecule