Chapter 4, Problem 4.43AP

(a)

Interpretation Introduction

Interpretation:

The Lewis structure of hydride ion and sodium hydride has to be drawn.  Also, the consistency of high melting point with Lewis structure has to be explained.

Concept Introduction:

Lewis structure: This is the only way to show the sharing of electrons between atom in polar covalent bonds or covalent bond.  This is often called Lewis structure.  This structure denotes valence electrons of an atom by dots and also it shows the way of valence electron distributed within a molecule.

(b)

Interpretation Introduction

Interpretation:

The gas evolved when sodium hydride is added slowly to water has to be identified.  Also, the reason for basic nature of the resulting solution has to be given.

Concept Introduction:

Position of equilibrium in acid-base reaction:

In an acid-base reaction, the position of equilibrium always favors reaction of the stronger acid and stronger base to form the weaker acid and weaker base. Therefore, the major species present at equilibrium in an acid-base reaction are weaker acid and weaker base.  The reaction equilibrium shifts to a direction where weaker acid and weaker base is formed.  Acids with greater ${\text{pK}}_{\text{a}}$ values are weak acids and base with greater ${\text{pK}}_{\text{b}}$ values are weaker base.

(c)

Interpretation Introduction

Interpretation:

Using curved arrows to indicate flow of electrons, a reaction equation between hydride ion and 1-butylene has to be given.