Chapter 2, Problem 25P

Interpretation Introduction

Interpretation:

The structural formula of a compounds of molecular formula ${\text{C}}_4{\text{H}}_8{\text{Cl}}_2$ in which all the carbons belong to methylene groups and of the molecular formula ${\text{C}}_4{\text{H}}_8{\text{Cl}}_2$ in which none of the carbons belong to methylene groups are to be drawn.

Concept introduction:

A methylene group is a $-{\text{CH}}_2-$ group.

Each carbon atom can, at the most, form four bonds. Each chlorine and hydrogen atom forms one bond.

In the structural formula, when all the four carbon atoms are present as methylene groups, there will be four $-{\text{CH}}_2-$ groups. The other atoms must be arranged such that they do not violate the octet rule for the carbon atom.

If there is no methylene group in the structural formula, then there will be methyl $-{\text{CH}}_3-$ and methine $-\text{CH}-$ groups present. Other atoms will be arranged such that the octet rule for carbon is not violated.