PROBLEM 24.17 - Organic Chemistry

Question

Question: Draw the products of each acid–base reaction. Indicate whether equilibrium favors the reactants or products.

a.

b.

c.

Step-by-Step Solution

Answer

Answer

a.

b.

c.

Equilibrium

The pK_a  of many protonated amines is 10–11. So, the  pK_a of the starting acid must be less than 10 for the equilibrium to favor the products. 

Amines are thus readily protonated by strong inorganic acids, such as HCl and H₂SO₄  and by carboxylic acid (organic acid) as well.

Explanation

a. The reaction of the butane amine is represented as

pK_a values of HCl is -7

The pK_a  of the product is 10. Therefore, the product is a weaker acid.

b. The reaction of the piperidine with water does not favor the product, as shown below. 

Favored equilibrium 

c. The reaction of the given amine is represented a

pK_a value of CH₃COOH is 4.2

pK_a  (CH₃)₂ NH₂⁺   is 10.7