Chapter 13, Problem 13.4P

Interpretation Introduction

(a)

Interpretation: The expected molecular ions of the given compounds are to be stated.

Concept introduction: Molecular ion is the radical cation which is formed by ejection of electrons from a molecule when a beam of high-energy electrons are bombarded on it.

Answer to Problem 13.4P

The expected molecular ions of ${\text{C}}_{\text{4}}{\text{H}}_{\text{9}}\text{Cl}$ are ${\left[{\text{C}}_4{\text{H}}_9{}^{35}\text{Cl}\right]}^{+·}$ and ${\left[{\text{C}}_4{\text{H}}_9{}^{37}\text{Cl}\right]}^{+·}$.

Explanation of Solution

The molecular formula of the compound is ${\text{C}}_{\text{4}}{\text{H}}_{\text{9}}\text{Cl}$. Chlorine atom has two isotopes ${}^{\text{35}}\text{Cl}$ and ${}^{\text{37}}\text{Cl}$.

The molecular formula of the compound with $\left({}^{\text{35}}\text{Cl}\right)$ is ${\text{C}}_4{\text{H}}_9{}^{35}\text{Cl}$.

The molar mass of ${\text{C}}_4{\text{H}}_9{}^{35}\text{Cl}$ is $\text{92 g/mol}$.

Hence, the mass of the molecular ion ${\left[{\text{C}}_4{\text{H}}_9{}^{35}\text{Cl}\right]}^{+·}$ is $m/z=92$.

The molecular formula of the compound with $\left({}^{\text{37}}\text{Cl}\right)$ is ${\text{C}}_4{\text{H}}_9{}^{37}\text{Cl}$.

The molar mass of ${\text{C}}_4{\text{H}}_9{}^{37}\text{Cl}$ is $\text{94 g/mol}$.

Hence, the mass of the molecular ion ${\left[{\text{C}}_4{\text{H}}_9{}^{37}\text{Cl}\right]}^{+·}$ is $m/z=94$.

Conclusion

The expected molecular ions of ${\text{C}}_{\text{4}}{\text{H}}_{\text{9}}\text{Cl}$ are ${\left[{\text{C}}_4{\text{H}}_9{}^{35}\text{Cl}\right]}^{+·}$ and ${\left[{\text{C}}_4{\text{H}}_9{}^{37}\text{Cl}\right]}^{+·}$.

Interpretation Introduction

(b)

Interpretation: The expected molecular ions of the given compounds are to be stated.

Concept introduction: Molecular ion is the radical cation which is formed by ejection of electrons from a molecule when a beam of high-energy electrons are bombarded on it.

Answer to Problem 13.4P

The expected molecular ion of ${\text{C}}_{\text{3}}{\text{H}}_{\text{7}}\text{F}$ is ${\left[{\text{C}}_{\text{3}}{\text{H}}_{\text{7}}\text{F}\right]}^{+·}$.

Explanation of Solution

The molecular formula of the compound is ${\text{C}}_{\text{3}}{\text{H}}_{\text{7}}\text{F}$.

The molar mass of ${\text{C}}_{\text{3}}{\text{H}}_{\text{7}}\text{F}$ is $\text{62 g/mol}$.

Hence, the mass of the molecular ion ${\left[{\text{C}}_{\text{3}}{\text{H}}_{\text{7}}\text{F}\right]}^{+·}$ is $m/z=62$.

Conclusion

The expected molecular ion of ${\text{C}}_{\text{3}}{\text{H}}_{\text{7}}\text{F}$ is ${\left[{\text{C}}_{\text{3}}{\text{H}}_{\text{7}}\text{F}\right]}^{+·}$.

Interpretation Introduction

(c)

Interpretation: The expected molecular ions of the given compounds are to be stated.

Concept introduction: Molecular ion is the radical cation which is formed by ejection of electrons from a molecule when a beam of high-energy electrons are bombarded on it.

Answer to Problem 13.4P

The expected molecular ion of ${\text{C}}_{\text{4}}{\text{H}}_{\text{11}}\text{N}$ is ${\left[{\text{C}}_{\text{4}}{\text{H}}_{\text{11}}\text{N}\right]}^{+·}$.

Explanation of Solution

The molecular formula of the compounds is ${\text{C}}_{\text{4}}{\text{H}}_{\text{11}}\text{N}$.

The molar mass of ${\text{C}}_{\text{4}}{\text{H}}_{\text{11}}\text{N}$ is $\text{73 g/mol}$.

Hence, the mass of the molecular ion ${\left[{\text{C}}_{\text{4}}{\text{H}}_{\text{11}}\text{N}\right]}^{+·}$ is $m/z=73$.

Conclusion

The expected molecular ion of ${\text{C}}_{\text{4}}{\text{H}}_{\text{11}}\text{N}$ is ${\left[{\text{C}}_{\text{4}}{\text{H}}_{\text{11}}\text{N}\right]}^{+·}$.

Interpretation Introduction

(d)

Interpretation: The expected molecular ions of the given compounds are to be stated.

Concept introduction: Molecular ion is the radical cation which is formed by ejection of electrons from a molecule when a beam of high-energy electrons is bombarded on it.

Answer to Problem 13.4P

The expected molecular ion of ${\text{C}}_{\text{4}}{\text{H}}_{\text{4}}{\text{N}}_{\text{2}}$ is ${\left[{\text{C}}_{\text{4}}{\text{H}}_{\text{4}}{\text{N}}_{\text{2}}\right]}^{+·}$.

Explanation of Solution

The molecular formula of the compound is ${\text{C}}_{\text{4}}{\text{H}}_{\text{4}}{\text{N}}_{\text{2}}$.

The molar mass of ${\text{C}}_{\text{4}}{\text{H}}_{\text{4}}{\text{N}}_{\text{2}}$ is $\text{80 g/mol}$.

Hence, the mass of the molecular ion ${\left[{\text{C}}_{\text{4}}{\text{H}}_{\text{4}}{\text{N}}_{\text{2}}\right]}^{+·}$ is $m/z=80$.

Conclusion

The expected molecular ion of ${\text{C}}_{\text{4}}{\text{H}}_{\text{4}}{\text{N}}_{\text{2}}$ is ${\left[{\text{C}}_{\text{4}}{\text{H}}_{\text{4}}{\text{N}}_{\text{2}}\right]}^{+·}$.