Chapter 6, Problem 6.83P

Interpretation Introduction

(a)

Interpretation:

Products of each possible proton transfer reaction are to be written.

Concept introduction:

A proton transfer reaction is the one in which a Bronsted Lowry base reacts with a Bronsted Lowry acid. A Bronsted Lowry base is a proton acceptor while a Bronsted Lowry acid is a proton donor. The proton is transferred from the acid to the base. The formal charge of the base increases by 1 and that for the acid decreases by 1. The conjugate acid is the species that the base becomes after picking up a proton, and the conjugate base is the species that the acid becomes after losing a proton. A proton transfer reaction is a concerted reaction – that is single step.

Interpretation Introduction

(b)

Interpretation:

Among the two possible proton transfer reactions, the reaction that is more energetically favorable is to be determined.

Concept introduction:

Proton transfer reactions favor the side opposite the stronger acid (i.e., opposite the lower pKa). When comparing two uncharged acids, the stronger acid is the one whose negatively charged conjugate base is more stable. If the conjugate base formed is more stable, then the acid will be stronger. An anion becomes more stable as the electronegativity of the atom bearing the negative charge increases. When comparing two positively charged acids, the stronger acid is the one that is less stable.