Chapter 1, Problem 1.55P

Interpretation Introduction

(a)

Interpretation:

All resonance contributors for sulfuric acid ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ (the S atom is bonded to four O atoms) are to be drawn.

Concept introduction:

If a species having two or more valid Lewis structures, then its resonance structure exists. Resonance structures are imaginary; true species is represented by the resonance hybrid. The resonance structures are differed by the placement of their valence electrons, and not their atoms. Resonance structures with a greater number of atoms having an octet complete, more covalent bonds, and fewer atoms having a non-zero formal charge are considered to be stable. While drawing resonance structures curved arrows are used. The movement of a pair of electrons is indicated by a curved arrow. A curved arrow originates from a lone pair of electrons or from a covalent double or triple bond to indicate the specific pair of electrons that are being moved. The arrow points to an atom if the electrons being moved become a lone pair. Otherwise, the arrow points to the center of an existing bond to represent the formation of a new double/triple bond. A resonance structure can be drawn if a lone pair of electrons on an atom is adjacent with multiple bonds or an incomplete octet on an atom is adjacent to multiple bonds or there is a ring of alternating single and multiple bonds.

Interpretation Introduction

(b)

Interpretation:

Resonance hybrid for ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ molecule is to be drawn.

Concept introduction:

A resonance hybrid structure is a weighted average structure of all the resonance contributors. A partial bond is represented in a resonance hybrid by a dashed line connecting the two atoms. In the resonance hybrid, the partial bonds are shown, which represent the atoms over which the electrons are delocalized. The resonance hybrid structure looks most like the lowest energy resonance structure and it is the most stable structure. The more stable resonance structures have a) a greater number of atoms having octet complete, b) more number of covalent bonds, and c) fewer atoms having a non-zero formal charge.

Interpretation Introduction

(c)

Interpretation:

The resonance structures of ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ molecule that contribute the least to the resonance hybrid is/are to be identified.

Concept introduction:

A resonance hybrid structure is a weighted average structure of all the resonance contributors. A partial bond is represented in a resonance hybrid by a dashed line connecting the two atoms. In the resonance hybrid, the partial bonds are shown, which represent the atoms over which the electrons are delocalized. The resonance hybrid structure looks most like the lowest energy resonance structure and it is the most stable structure. The more stable resonance structures have a) a greater number of atoms having octet complete, b) more number of covalent bonds, and c) fewer atoms having a non-zero formal charge.