i. Which of the following solutions has the lowest pH (more acidic). Explain you answers.

a. a 0.1 M solution of a strong acid or a 0.1 M solution of a weak acid.
b. a 0.1 M solution of an acid with Ka=2×10-3 or one with Ka=8×10-6
c. a 0.1 M solutions of a base with pKb=4.5 or one with pKb=6.5
ii.. Cocaine is a weak organic base with a chemical formula C17H21NO4. A 0.10M aqueous solution of cocaine was found to have a pH of 8.53. Calculate Kb for cocaine.