For the following acid–base pairs, (iv) calculate K_eq;
(e)

Write the K_eq expression for the following acid–base reactions. [You don't need to calculate K_eq here.]

(c)

Parts (a)–(d) of this assessment assist in the development of what will become a common theme in organic reactions and should be worked in order. [Think carefully about how each question relates to the others.]

(c) Without worrying about the mechanism of the reaction, estimate an equilibrium constant for the following carbonyl addition reaction based on the relative stability of the Lewis bases.

Calculate the equilibrium constant for the reaction of ethylamine and propanoic acid. Which side is favored?

How do you know that a proton with a low pK_a value is acidic (besides 'I just remember')?

Given that the indicated pK_a values correspond to the acid dissociation reactions shown, calculate the ratio of acid to conjugate base for the reactions shown.

(a)

Using pK_a values, calculate an approximate K_eq value for the following substitution reaction.

Amino acids exist predominantly in one of the following forms. Which is it? Explain your answer.

At what pH is the concentration of a compound, with a pK_a = 4.6, 10 times greater in its basic form than in its acidic form?