Chapter U2, Problem 6RE

(a)

Interpretation Introduction

Interpretation :

Structural formula of the polar molecule with molecular formula C₃H₈O must be drawn.

Concept Introduction :

Structural formula represents the structure of a compound in which the arrangements of atoms are shown.

Answer to Problem 6RE

Structural formula is drawn below for the polar molecule with molecular formula C₃H₈O.

Explanation of Solution

The molecular formula C₃H₈O represents isomeric ether and alcohols. Alcohols are polar than ether. Two alcohols are possible with the formula. One is primary alcohol and another is secondary alcohol. Primary alcohol (Propan-1-ol) is drawn.

b)

Interpretation Introduction

Interpretation :

Lewis structure must be drawn and shared electrons and lone pair electrons must be labeled.

Concept Introduction :

Lewis dot structure is the representation of molecule in which valence electrons are shown as dots.

Answer to Problem 6RE

Lewis dot structure is given below.

All the dots are bond pair electrons except the two electron pairs on O atom (shown in red) are lone pair electrons.

Explanation of Solution

Lewis electron dot structure is shown. All the carbon is bonded with 4 atoms and the oxygen atom is bonded with two atoms. There are all single bonds. Two lone pairs are there on O atom.

c)

Interpretation Introduction

Interpretation :

The dipoles must be identified.

Concept Introduction :

A molecule will have dipoles if there is electronegativity difference between the two atoms forming the bond.

Answer to Problem 6RE

The dipoles are shown.

Explanation of Solution

Oxygen will have partial negative charge as it has more electronegativity. Similarly H atom will have partial positive charge as it has less electronegativity.

Each C-H bond is also a dipole in which C is the negative pole and H is the positive pole as C has more electronegativity as compared to H.

d)

Interpretation Introduction

Interpretation :

The geometric shape around each carbon atom must be named.

Concept Introduction :

The geometric shape around an atom depends on the number of total electron pairs.

Answer to Problem 6RE

Each carbon has tetrahedral geometry.

Explanation of Solution

Each carbon is bonded with total 4 atoms including hydrogen atom, carbon atom and oxygen atom. There is no lone pair of electrons on any carbon atom. Thus, each carbon will be tetrahedral.

e)

Interpretation Introduction

Interpretation :

The name of the compound must be given with proper reasoning.

Concept Introduction :

A molecule can be named using IUPAC rule. The molecule will have a trivial name also.

The molecule has three carbons and -OH as a functional group.

Answer to Problem 6RE

The name of the molecule is Propan-1-ol.

Explanation of Solution

The structure is given as follows:

The numbering is done giving priority to the carbon bearing the functional (-OH) group. Total three carbons are there. The functional group is at carbon 1. So, the IUPAC name is propn-1-ol. The trivial name is n-propyl alcohol. As the -OH group is attached with normal propyl (1 degree) group.