Chapter 3, Problem 3.20P

Interpretation Introduction

(a)

Interpretation: The functional groups in the ball-and-stick model of pantothenic acid, vitamin ${\text{B}}_{\text{5}}$ are to be identified.

Concept introduction: Functional groups are specific substituents present in the molecule that is responsible for the characteristic chemical reactions. For example, functional groups possess a carbonyl group includes aldehydes, ketones, carboxylic acids, amides, esters and acid chlorides.

Interpretation Introduction

(b)

Interpretation: The site at which pantothenic acid can form hydrogen bond to water molecule is to be predicted.

Concept introduction: Hydrogen bonding is the strongest intermolecular forces present between the substances. A hydrogen atom participates in hydrogen bonding if it is bonded to an electronegative atom like fluorine, oxygen or nitrogen.

Interpretation Introduction

(c)

Interpretation: The solubility of pantothenic acid in water is to be predicted.

Concept introduction: The general rule of solubility is like dissolves like, in other words, polar compounds dissolve in polar solvents, and non-polar compounds dissolve in non-polar solvents.

The polar solvent such as water has partial $+\text{ or }-$ charges that can interact with the partial $+\text{ or }-$ charges of a polar compound.