The chemical name for aspirin is acetylsalicylic acid. It is believed that the analgesic and other desirable properties of aspirin are due not to the aspirin itself but rather to the simpler compound salicylic acid, C₆H₄(OH)CO₂H, which results from the breakdown of aspirin in the stomach.

(a) Give approximate values for the following bond angles in the acid: (i) C—C—C in the ring; (ii) O—C=O; (iii) either of the
C—O—H angles; and (iv) C—C—H.
(b) What is the hybridization of the C atoms of the ring? Of the C atom in the —CO₂H group?
(c) Experiment shows that 1.00 g of the acid will dissolve in 460 mL of water. If the pH of this solution is 2.4, what is K_a for the acid?
(d) If you have salicylic acid in your stomach and if the pH of gastric juice is 2.0, calculate the percentage of salicylic acid that will be present in the stomach in the form of the salicylate ion, C₆H₄(OH)CO₂⁻.
(e) Assume you have 25.0 mL of a 0.014 M solution of salicylic acid and titrate it with 0.010 M NaOH. What is the pH at the halfway point of the titration? What is the pH at the equivalence
point?

Transcribed Image Text:

0 C-OH ОН Salicylic acid