Chapter 18, Problem 18.145P

(a)

Interpretation Introduction

Interpretation:

The two possible structures for chloral hydrate have to be identified.

Concept introduction:

Hydrogen bond:

A hydrogen bond is an electrostatic attraction between a hydrogen atom and more electronegative atom such as nitrogen (N), oxygen (O), or fluorine (F) atoms.

The Lewis structure is based on the concept of the octet rule so that the electrons shared in each atom should have 8 electrons in its outer shell.

Sometimes the chemical bonding of a molecule cannot be represented using a single Lewis structure. In these cases, the chemical bonding is described by delocalization of electrons and is known as resonance.

All the possible resonance structures are imaginary whereas the resonance hybrid is real.

These structures will differ only in the arrangement of the electrons not in the relative position of the atomic nuclei.

Lewis structure for any molecule is drawn by using the following steps,

First the skeletal structure for the given molecule is drawn then the total number of valence electrons for all atoms present in the molecule is determined.

The next step is to subtract the electrons present in the total number of bonds present in the skeletal structure of the molecule with the total valence electrons such that considering each bond contains two electrons with it.

Finally, the electrons which got after subtractions have to be equally distributed such that each atom contains eight electrons in its valence shell.

(b)

Interpretation Introduction

Interpretation:

The spectroscopic method that used to identify the real structure has to be given.

Concept introduction:

Spectroscopy: it is study of the interaction of matter and electromagnetic radiation, a continuum of different types of electromagnetic radiation each associated with a particular energy range makes up the electromagnetic spectrum.

IR frequency (cm^-1): It is the number of wave crests that pass by a given point in one second frequency has units of hertz (Hz).

Stretch vibrations: it is a vibration occurring along the line of the bond a stretching vibration changes the bond length.

Bending vibrations: It is a vibration that does not occur along the line of the bond, bending vibration changes the bond angle.