Chapter 23.6, Problem 23.8P

(a)

Interpretation Introduction

Interpretation:

Reason for why $-N{H}_3{}^{+}$ group of the conjugate acid of alanine is a stronger acid than the $-N{H}_3{}^{+}$ group of the conjugate acid of isopropylamine has to be given.

Concept Introduction:

According to the explanations by Bronsted-Lowry, if a species loses a proton then it is an acid whereas if a species receives one proton, then it is base.

If a base receives one proton, then the formed species is a conjugate acid whereas an acid lose one proton, then the formed species is a conjugated base.

Stronger the acid weaker it’s conjugate base and vice versa.

Deactivators are electron withdrawing groups attached to the benzenes that have either positive charge or an atom with high electronegativity.  They are meta directors.

Activators are electron donating groups attached to the benzenes that have either electron density that is able to push into benzene ring or a lone pair of electrons. They are ortho–para directing.

(b)

Interpretation Introduction

Interpretation:

Reason for why the $-COOH$ group of the conjugate acid of alanine is a stronger acid than the $-COOH$ group of propanoic acid has to be given.

Concept introduction:

According to the explanations by Bronsted-Lowry, if a species loses a proton then it is an acid whereas if a species receives one proton, then it is base.

If a base receives one proton, then the formed species is a conjugate acid whereas an acid lose one proton, then the formed species is a conjugated base.

Inductive effect: It is an electronic effect occurs due to the difference in the electronegativity of atoms in a bond.  This unequal sharing of electrons in the bond leads to a permanent dipole.