Chapter 7.8, Problem 29CC

(a)

Interpretation Introduction

Interpretation:

The given substrates should be determined that whether they favor ${\text{S}}_{\text{N}}2$ or ${\text{S}}_{\text{N}}\text{1}$ reaction mechanism.

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. Formation of more stable carbocation and the leaving group present in the substrate plays very important role in the reactivity of ${\text{S}}_{\text{N}}\text{1}$ reaction. The tertiary carbo cation substrate favors this mechanism strongly since it is the most stable species among the carbo cation.

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

Carbocation stability order:

Carbo-cation Rearrangement:

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

Nucleophile: Nucleophiles are electron rich compounds which donates electrons to electrophilic compounds which results in bond formation.

Nucleophilic nature depends on the negative charge present in the molecule, the solvent in which it present and the electronegativity of the atom.

Solvent: it is substance which dissolves the chemical substrate. They are classified as polar protic and polar aprotic solvent.

Polar protic solvent: It contains at least one $\text{H}$ atom directly bonded to electronegative atom. This solvent favors ${\text{S}}_{\text{N}}\text{1}$ reaction hence polar solvent stabilizes the cations by using the lone pair of electrons present in the solvent and stabilize the anions by forming H-bonding since they contain hydrogen atoms.

Electropositive: The tendency of a metal to lose electrons readily in chemical reaction.

(c)

Interpretation Introduction

Interpretation:

The given substrates should be determined that whether they favor ${\text{S}}_{\text{N}}2$ or ${\text{S}}_{\text{N}}\text{1}$ reaction mechanism.

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. Formation of more stable carbocation and the leaving group present in the substrate plays very important role in the reactivity of ${\text{S}}_{\text{N}}\text{1}$ reaction. The tertiary carbo cation substrate favors this mechanism strongly since it is the most stable species among the carbo cation.

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

Carbocation stability order:

Carbo-cation Rearrangement:

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

Nucleophile: Nucleophiles are electron rich compounds which donates electrons to electrophilic compounds which results in bond formation.

Nucleophilic nature depends on the negative charge present in the molecule, the solvent in which it present and the electronegativity of the atom.

Solvent: it is substance which dissolves the chemical substrate. They are classified as polar protic and polar aprotic solvent.

Polar protic solvent: It contains at least one $\text{H}$ atom directly bonded to electronegative atom. This solvent favors ${\text{S}}_{\text{N}}\text{1}$ reaction hence polar solvent stabilizes the cations by using the lone pair of electrons present in the solvent and stabilize the anions by forming H-bonding since they contain hydrogen atoms.

Electropositive: The tendency of a metal to lose electrons readily in chemical reaction.

(e)

Interpretation Introduction

Interpretation:

The given substrates should be determined that whether they favor ${\text{S}}_{\text{N}}2$ or ${\text{S}}_{\text{N}}\text{1}$ reaction mechanism.

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. Formation of more stable carbocation and the leaving group present in the substrate plays very important role in the reactivity of ${\text{S}}_{\text{N}}\text{1}$ reaction. The tertiary carbo cation substrate favors this mechanism strongly since it is the most stable species among the carbo cation.

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

Carbocation stability order:

Carbo-cation Rearrangement:

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

Nucleophile: Nucleophiles are electron rich compounds which donates electrons to electrophilic compounds which results in bond formation.

Nucleophilic nature depends on the negative charge present in the molecule, the solvent in which it present and the electronegativity of the atom.

Solvent: it is substance which dissolves the chemical substrate. They are classified as polar protic and polar aprotic solvent.

Polar protic solvent: It contains at least one $\text{H}$ atom directly bonded to electronegative atom. This solvent favors ${\text{S}}_{\text{N}}\text{1}$ reaction hence polar solvent stabilizes the cations by using the lone pair of electrons present in the solvent and stabilize the anions by forming H-bonding since they contain hydrogen atoms.

Electropositive: The tendency of a metal to lose electrons readily in chemical reaction.

(h)

Interpretation Introduction

Interpretation:

The given substrates should be determined that whether they favor ${\text{S}}_{\text{N}}2$ or ${\text{S}}_{\text{N}}\text{1}$ reaction mechanism.

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. Formation of more stable carbocation and the leaving group present in the substrate plays very important role in the reactivity of ${\text{S}}_{\text{N}}\text{1}$ reaction. The tertiary carbo cation substrate favors this mechanism strongly since it is the most stable species among the carbo cation.

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

Carbocation stability order:

Carbo-cation Rearrangement:

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

Nucleophile: Nucleophiles are electron rich compounds which donates electrons to electrophilic compounds which results in bond formation.

Nucleophilic nature depends on the negative charge present in the molecule, the solvent in which it present and the electronegativity of the atom.

Solvent: it is substance which dissolves the chemical substrate. They are classified as polar protic and polar aprotic solvent.

Polar protic solvent: It contains at least one $\text{H}$ atom directly bonded to electronegative atom. This solvent favors ${\text{S}}_{\text{N}}\text{1}$ reaction hence polar solvent stabilizes the cations by using the lone pair of electrons present in the solvent and stabilize the anions by forming H-bonding since they contain hydrogen atoms.

Electropositive: The tendency of a metal to lose electrons readily in chemical reaction.

 (b)

Interpretation Introduction

Concept introduction:

${\text{S}}_{\text{N}}2$Reaction: It is a nucleophilic substitution reaction in which the rate determining step depends on both of the molecules involved. The bond making and the bond breaking process happens simultaneously in this reaction.

Structure of the substrate plays an major role in the reactivity of ${\text{S}}_{\text{N}}2$ reaction. If the substrate is more substituted then the rate of the reaction will becomes slower. Since the mechanism of ${\text{S}}_{\text{N}}2$ reaction proceeds through backside attack on the substrate, it depends on steric factor that if more groups attached near the leaving group the reactivity becomes slower.

Leaving group: it is a fragment that leaves the chemical compound with pair of electrons in a heterolytic bond cleavage. The ${\text{S}}_{\text{N}}2$ reactivity increases in molecule with better leaving group.

Polar aprotic solvent: It does not contain $\text{H}$ atoms directly bonded to electronegative atom. This solvent favors ${\text{S}}_{\text{N}}2$ reaction hence aprotic solvent stabilizes only the cations by using the lone pair of electrons present in the solvent.

(d)

Interpretation Introduction

Concept introduction:

${\text{S}}_{\text{N}}2$Reaction: It is a nucleophilic substitution reaction in which the rate determining step depends on both of the molecules involved. The bond making and the bond breaking process happens simultaneously in this reaction.

Structure of the substrate plays an major role in the reactivity of ${\text{S}}_{\text{N}}2$ reaction. If the substrate is more substituted then the rate of the reaction will becomes slower. Since the mechanism of ${\text{S}}_{\text{N}}2$ reaction proceeds through backside attack on the substrate, it depends on steric factor that if more groups attached near the leaving group the reactivity becomes slower.

Leaving group: it is a fragment that leaves the chemical compound with pair of electrons in a heterolytic bond cleavage. The ${\text{S}}_{\text{N}}2$ reactivity increases in molecule with better leaving group.

Polar aprotic solvent: It does not contain $\text{H}$ atoms directly bonded to electronegative atom. This solvent favors ${\text{S}}_{\text{N}}2$ reaction hence aprotic solvent stabilizes only the cations by using the lone pair of electrons present in the solvent.

(f)

Interpretation Introduction

Concept introduction:

${\text{S}}_{\text{N}}2$Reaction: It is a nucleophilic substitution reaction in which the rate determining step depends on both of the molecules involved. The bond making and the bond breaking process happens simultaneously in this reaction.

Structure of the substrate plays an major role in the reactivity of ${\text{S}}_{\text{N}}2$ reaction. If the substrate is more substituted then the rate of the reaction will becomes slower. Since the mechanism of ${\text{S}}_{\text{N}}2$ reaction proceeds through backside attack on the substrate, it depends on steric factor that if more groups attached near the leaving group the reactivity becomes slower.

Leaving group: it is a fragment that leaves the chemical compound with pair of electrons in a heterolytic bond cleavage. The ${\text{S}}_{\text{N}}2$ reactivity increases in molecule with better leaving group.

Polar aprotic solvent: It does not contain $\text{H}$ atoms directly bonded to electronegative atom. This solvent favors ${\text{S}}_{\text{N}}2$ reaction hence aprotic solvent stabilizes only the cations by using the lone pair of electrons present in the solvent.

(g)

Interpretation Introduction

Concept introduction:

${\text{S}}_{\text{N}}2$Reaction: It is a nucleophilic substitution reaction in which the rate determining step depends on both of the molecules involved. The bond making and the bond breaking process happens simultaneously in this reaction.

Structure of the substrate plays an major role in the reactivity of ${\text{S}}_{\text{N}}2$ reaction. If the substrate is more substituted then the rate of the reaction will becomes slower. Since the mechanism of ${\text{S}}_{\text{N}}2$ reaction proceeds through backside attack on the substrate, it depends on steric factor that if more groups attached near the leaving group the reactivity becomes slower.

Leaving group: it is a fragment that leaves the chemical compound with pair of electrons in a heterolytic bond cleavage. The ${\text{S}}_{\text{N}}2$ reactivity increases in molecule with better leaving group.

Polar aprotic solvent: It does not contain $\text{H}$ atoms directly bonded to electronegative atom. This solvent favors ${\text{S}}_{\text{N}}2$ reaction hence aprotic solvent stabilizes only the cations by using the lone pair of electrons present in the solvent.