Chapter 9.3, Problem 6ATS

(a)

Interpretation Introduction

Interpretation:

The structure and mechanism for formation of lithium acetylide has to be given.

Concept introduction:

Mechanism of the reaction is the step-by-step description of the process by which reactants are changed into products.

Curved arrows show the bonds that are formed and the bonds that are broken in a reaction.

(b)

Interpretation Introduction

Interpretation:

The deprotonation of acetylene can be done or not by given bases has to be determined.

Concept Introduction:

Acidity of terminal alkynes:

Acidity of alkynes depends on $\text{pKa}$ of it.  Increase in $\text{pKa}$ value, decreases acidity of alkynes and vice-versa.  During deprotonation of alkynes, if the base added is stronger than it results in formation of weaker base and favors the equilibrium.  But the added base produces stronger base, then the acid is weaker acid.