Rank the following from strongest base to weakest base:
b.

For the bases shown, draw the conjugate acid and identify a pK_a value from Table 4.5 that would help you accurately estimate its stability.

(d)

a. Which is a stronger base: CH₃COO⁻ or HCOO⁻? (The pK_a of CH₃COOH is 4.8; the pK_a of HCOOH is 3.8.)

b. Which is a stronger base: HO⁻ or ^-NH₂? (The pK_a of H2O is 15.7; the pK_a of NH3 is 36.)

c. Which is a stronger base: H₂O or CH₃OH? (The pK_a of H3O+ is −1.7; the pK_a of CH₃O⁺H₂ is −2.5.)

A medicinal chemist needed to deprotonate acetylene ( HC≡CH ) for use in a coupling reaction. Among the options given, which base(s) could be used for this process?

For each compound, indicate the atom that is most apt to be protonated.

a.

b.

c.

Citrus fruits are rich in citric acid, a compound with three COOH groups. Explain the following:

b. The third pK_a is greater than the pKa of acetic acid.

Given the structure of ascorbic acid (vitamin C):

(a) Is ascorbic acid a carboxylic acid?

(b) Compare the acid strength of ascorbic acid (pK_a = 4.71) with acetic acid.

Which is a stronger base: ethoxide ion or acetate ion? Give pK_b values (without looking them up) to support your choice.

Given the structure of ascorbic acid (vitamin C):

(c) Predict which proton in ascorbic acid is the most acidic.

(d) Draw the form of ascorbic acid that is present in the body (aqueous solution, pH = 7.4)