Chapter 6, Problem 6.45P

Interpretation Introduction

(a) Interpretation:

It is to be determined whether the given reactant is suitable for a reaction involving ethanol as a solvent with respect to leveling effect.

Concept introduction:

The solvent affects the properties of bases and acids. This effect is referred as leveling effect. For an acid-base reaction, the basicity of the solvent levels or limits the strength of the strong acid. Similarly, the acidity of the solvent levels the strength of the strong base. With respect to the leveling effect, a solvent is unsuitable for a particular reactant R if R is a stronger acid that the solvent’s conjugate acid (i.e., R has the lower pKa) or if R is a stronger base than the solvent’s conjugate base (i.e., the conjugate acid of R has a higher pKa than the solvent).

Answer to Problem 6.45P

With respect to the leveling effect, ethanol is not a suitable solvent for a reaction involving ${}^{\text{Θ}}{\text{NH}}_{\text{2}}$ as a reactant.

Explanation of Solution

The reaction of ${}^{\text{Θ}}{\text{NH}}_{\text{2}}$ with ethanol is shown below:

Ethanol, ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH}$ ($\text{pKa = 16}$), is a stronger acid than ammonia, ${\text{NH}}_{\text{3}}$ ($\text{pKa = 36}$). The product side of the reaction is most favored because the stronger acid ethanol (${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH}$) is on the reactant side. ${}^{\text{Θ}}{\text{NH}}_{\text{2}}$ does not change the properties of ethanol. Therefore, ethanol is not a suitable solvent for ${}^{\text{Θ}}{\text{NH}}_{\text{2}}$ because the equilibrium lies to the product side.

Conclusion

The solvent effect on the reactant is determined with respect to the leveling effect.

Interpretation Introduction

(b)

Interpretation:

It is to be determined whether the given reactant is suitable for a reaction involving ethanol as a solvent with respect to leveling effect.

Concept introduction:

The solvent affects the properties of bases and acids. This effect is referred as leveling effect. For an acid-base reaction, the basicity of the solvent levels or limits the strength of the strong acid. Similarly, the acidity of the solvent levels the strength of the strong base. With respect to the leveling effect, a solvent is unsuitable for a particular reactant R if R is a stronger acid that the solvent’s conjugate acid (i.e., R has the lower pKa) or if R is a stronger base than the solvent’s conjugate base (i.e., the conjugate acid of R has a higher pKa than the solvent).

Answer to Problem 6.45P

With respect to the leveling effect, ethanol is a suitable solvent for a reaction involving ${\text{CH}}_{\text{3}}{\text{COO}}^{\Theta }$ as a reactant.

Explanation of Solution

The reaction of the acetate ion ${\text{CH}}_{\text{3}}{\text{COO}}^{\Theta }$ with ethanol is shown below:

Acetic acid, ${\text{CH}}_{\text{3}}\text{COOH}$ ($\text{pKa = 4}\text{.75}$) is a stronger acid than Ethanol, ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH}$ ($\text{pKa = 16}$). The reactant side of the reaction is most favored because the stronger acid, ${\text{CH}}_{\text{3}}\text{COOH}$ is on the product side. ${\text{CH}}_{\text{3}}{\text{COO}}^{\Theta }$ changes the properties of ethanol. Therefore, ethanol is a suitable solvent for ${\text{CH}}_{\text{3}}{\text{COO}}^{\Theta }$ because the equilibrium lies to the reactant side.

Conclusion

The solvent effect on the reactant is determined with respect to the leveling effect.

Interpretation Introduction

(c)

Interpretation:

It is to be determined whether the given reactant is suitable for a reaction involving ethanol as a solvent with respect to leveling effect.

Concept introduction:

The solvent affects the properties of bases and acids. This effect is referred as leveling effect. For an acid-base reaction, the basicity of the solvent levels or limits the strength of the strong acid. Similarly, the acidity of the solvent levels the strength of the strong base. With respect to the leveling effect, a solvent is unsuitable for a particular reactant R if R is a stronger acid that the solvent’s conjugate acid (i.e., R has the lower pKa) or if R is a stronger base than the solvent’s conjugate base (i.e., the conjugate acid of R has a higher pKa than the solvent).

Answer to Problem 6.45P

With respect to the leveling effect, ethanol is a suitable solvent for a reaction involving chloride ion ${\text{Cl}}^{\text{Θ}}$ as a reactant.

Explanation of Solution

The reaction of chloride ion ${\text{Cl}}^{\text{Θ}}$ with ethanol is shown below:

Hydrochloric acid, $\text{HCl}$ ($\text{pKa = -7}$), is a stronger acid than Ethanol, ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH}$ ($\text{pKa = 16}$). The reactant side of the reaction is most favored because the stronger acid, $\text{HCl}$, is on the product side. ${\text{Cl}}^{\text{Θ}}$ changes the properties of ethanol. Therefore, ethanol is a suitable solvent for ${\text{Cl}}^{\text{Θ}}$ because the equilibrium lies to the reactant side.

Conclusion

The solvent effect on the reactant is determined with respect to the leveling effect.

Interpretation Introduction

(d)

Interpretation:

It is to be determined whether the given reactant is suitable for a reaction involving ethanol as a solvent with respect to leveling effect.

Concept introduction:

The solvent affects the properties of bases and acids. This effect is referred as leveling effect. For an acid-base reaction, the basicity of the solvent levels or limits the strength of the strong acid. Similarly, the acidity of the solvent levels the strength of the strong base. With respect to the leveling effect, a solvent is unsuitable for a particular reactant R if R is a stronger acid that the solvent’s conjugate acid (i.e., R has the lower pKa) or if R is a stronger base than the solvent’s conjugate base (i.e., the conjugate acid of R has a higher pKa than the solvent).

Answer to Problem 6.45P

With respect to the leveling effect, ethanol is a suitable solvent for a reaction involving phenoxide ion (${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{O}}^{\text{Θ}}$) as a reactant.

Explanation of Solution

The reaction of phenoxide ion (${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{O}}^{\text{Θ}}$) with ethanol is shown below:

Phenol, ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\text{OH}$ ($\text{pKa = 10}$), is a stronger acid than ethanol, ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH}$ ($\text{pKa = 16}$). The reactant side of the reaction is most favored because the stronger acid, ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}\text{OH}$, is on the product side. ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{O}}^{\text{Θ}}$ changes the properties of ethanol. Therefore, ethanol is a suitable solvent for the phenoxide ion (${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{O}}^{\text{Θ}}$) because the equilibrium lies to the reactant side.

Conclusion

The solvent effect on the reactant is determined with respect to the leveling effect.

Interpretation Introduction

(e)

Interpretation:

It is to be determined whether the given reactant is suitable for a reaction involving ethanol as a solvent with respect to leveling effect.

Concept introduction:

The solvent affects the properties of bases and acids. This effect is referred as leveling effect. For an acid-base reaction, the basicity of the solvent levels or limits the strength of the strong acid. Similarly, the acidity of the solvent levels the strength of the strong base. With respect to the leveling effect, a solvent is unsuitable for a particular reactant R if R is a stronger acid that the solvent’s conjugate acid (i.e., R has the lower pKa) or if R is a stronger base than the solvent’s conjugate base (i.e., the conjugate acid of R has a higher pKa than the solvent).

Answer to Problem 6.45P

With respect to the leveling effect, ethanol is a suitable solvent for a reaction involving ${\text{CN}}^{\text{Θ}}$ as a reactant.

Explanation of Solution

The reaction of cyanide ion ${\text{CN}}^{\text{Θ}}$ with ethanol is shown below:

Acetylene, $\text{HCN}$ ($\text{pKa = 9}\text{.2}$), is a stronger acid than ethanol, ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH}$ ($\text{pKa = 16}$). The reactant side of the reaction is most favored because the stronger acid, $\text{HCN}$, is on the product side. ${\text{CN}}^{\text{Θ}}$ changes the properties of ethanol. Therefore, ethanol is a suitable solvent for cyanide ion (${\text{CN}}^{\text{Θ}}$) because the equilibrium lies to the reactant side.

Conclusion

The solvent effect on the reactant is determined with respect to the leveling effect.

Interpretation Introduction

(f)

Interpretation:

It is to be determined whether the given reactant is suitable for a reaction involving ethanol as a solvent with respect to leveling effect.

Concept introduction:

The solvent affects the properties of bases and acids. This effect is referred as leveling effect. For an acid-base reaction, the basicity of the solvent levels or limits the strength of the strong acid. Similarly, the acidity of the solvent levels the strength of the strong base. With respect to the leveling effect, a solvent is unsuitable for a particular reactant R if R is a stronger acid that the solvent’s conjugate acid (i.e., R has the lower pKa) or if R is a stronger base than the solvent’s conjugate base (i.e., the conjugate acid of R has a higher pKa than the solvent).

Answer to Problem 6.45P

With respect to the leveling effect, ethanol is not a suitable solvent for a reaction involving ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{}^{\Theta }$ as a reactant.

Explanation of Solution

The reaction of propyl group ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{}^{\Theta }$ with ethanol is shown below:

Ethanol, ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH}$ ($\text{pKa = 16}$), is a stronger acid than propane, ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}$ ($\text{pKa = ~51}$). The product side of the reaction is most favored because the stronger acid, ethanol (${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH}$), is on the reactant side. ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{}^{\Theta }$ does not change the properties of ethanol. Therefore, ethanol is not a suitable solvent for ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{}^{\Theta }$ because the equilibrium lies to the product side.

Conclusion

The solvent effect on the reactant is determined with respect to the leveling effect.