Chapter 7, Problem 43PP

(a)

Interpretation Introduction

Interpretation: The rate for the given reaction should be analyzed for the given condition.

Concept Introduction:

${\text{S}}_{\text{N}}\text{1}$Reaction: it is a nucleophilic substitution reaction in which the rate determining step depends on one reactant. First step is the formation of more stable carbocation which is followed by the attack of nucleophile.

The rate of ${\text{S}}_{\text{N}}\text{1}$ depends only on the formation of the more stable carbocation present in the substrate. The reactivity increases with better leaving group in the substrate. It does not depends on the nucleophile present.

Carbocation: carbon ion that bears a positive charge on it.

Leaving group: it is a fragment that leaves a substrate in a chemical reaction with a pair of electrons via heterolytic bond cleavage.

Polar protic solvent: solvents that contains ${\text{H}}^{+}$ which is directly bonded to electronegative atom.

Electronegativity: it is the tendency of atoms to attract a lone pair of electrons towards itself in a substrate. Electronegativity property follows the trend that it increases across periods and decreases down the column in the periodic table.

Nucleophile - negatively charged species which donates electron pairs. Eg. ${\text{Cl}}^{\text{-}}$, ${\text{Br}}^{\text{-}}$ etc.,

(b)

Interpretation Introduction

Interpretation: The rate for the given reaction should be analyzed for the given condition.

Concept Introduction:

${\text{S}}_{\text{N}}\text{1}$Reaction: it is a nucleophilic substitution reaction in which the rate determining step depends on one reactant. First step is the formation of more stable carbocation which is followed by the attack of nucleophile.

The rate of ${\text{S}}_{\text{N}}\text{1}$ depends only on the formation of the more stable carbocation present in the substrate. The reactivity increases with better leaving group in the substrate. It does not depends on the nucleophile present.

Carbocation: carbon ion that bears a positive charge on it.

Leaving group: it is a fragment that leaves a substrate in a chemical reaction with a pair of electrons via heterolytic bond cleavage.

Polar protic solvent: solvents that contains ${\text{H}}^{+}$ which is directly bonded to electronegative atom.

Electronegativity: it is the tendency of atoms to attract a lone pair of electrons towards itself in a substrate. Electronegativity property follows the trend that it increases across periods and decreases down the column in the periodic table.

Nucleophile - negatively charged species which donates electron pairs. Eg. ${\text{Cl}}^{\text{-}}$, ${\text{Br}}^{\text{-}}$ etc.,