Chapter 4, Problem 4.49P

Interpretation Introduction

(a)

Interpretation:

IHD for the compound having the molecular formula ${\text{C}}_6{\text{H}}_6$ is to be determined.

Concept introduction:

In order to determine the IHD of a given molecular formula, first draw any saturated molecule that has the same number of each non-hydrogen atom as in the given formula. The general formula of a saturated hydrocarbon is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$, where n stands for the number of carbon atoms. The saturated molecule must not contain double bonds, triple bonds, or rings. Each atom should have its normal number of bonds and lone pairs to avoid formal charges. Thus, each carbon should have four bonds; each hydrogen should have one bond; each oxygen should have two bonds and two lone pairs, and each halogen must have one bond and three lone pairs of electrons. The next step is to determine how many more hydrogen atoms are there in this saturated molecule compared to the formula that is given. In the last step, the IHD is calculated by dividing that number of additional hydrogen atoms by 2.

Answer to Problem 4.49P

IHD for the compound having molecular formula ${\text{C}}_6{\text{H}}_6$ is $4$.

Explanation of Solution

The given molecular formula is ${\text{C}}_6{\text{H}}_6$. The general formula of a saturated hydrocarbon is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$, where n stands for the number of carbon atoms. According to this formula, the hydrocarbon having six carbon atoms must have $\text{(2x6) + 2 = 14}$ hydrogen atoms.

Thus, this saturated molecule has 8 additional hydrogen atoms as compared to the given molecular formula. IHD for the given molecular formula is calculated by dividing that number of additional hydrogen atoms by 2. Thus, IHD is $\text{8/2 = 4}$. Thus, IHD for the compound having molecular formula ${\text{C}}_6{\text{H}}_6$ is $4$.

Conclusion

The IHD for the compound with a given molecular formula is calculated by applying the steps above.

Interpretation Introduction

(b)

Interpretation:

IHD for the compound having the molecular formula ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{NO}}_2$ is to be determined.

Concept introduction:

In order to determine the IHD of a given molecular formula, first draw any saturated molecule that has the same number of each non-hydrogen atom as in the given formula. The general formula of a saturated hydrocarbon is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$, where n stands for the number of carbon atoms. The saturated molecule must not contain double bonds, triple bonds, or rings. Each atom should have its normal number of bonds and lone pairs to avoid formal charges. Thus, each carbon should have four bonds; each hydrogen should have one bond; each oxygen should have two bonds and two lone pairs, and each halogen must have one bond and three lone pairs of electrons. The next step is to determine how many more hydrogen atoms are there in this saturated molecule compared to the formula that is given. In the last step, the IHD is calculated by dividing that number of additional hydrogen atoms by 2.

Answer to Problem 4.49P

IHD for the compound having molecular formula ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{NO}}_2$ is $\text{5}$.

Explanation of Solution

The given molecular formula is ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{NO}}_2$. A saturated molecule is drawn containing six carbon atoms, one nitrogen atom, and two oxygen atoms simply by connecting all of these atoms in a row using single bonds only, as shown below:

It takes a total of 15 hydrogen atoms to saturate each carbon, nitrogen, and oxygen in this compound. Thus, this saturated molecule has 10 additional hydrogen atoms as compared to the given molecular formula. IHD for the given molecular formula is calculated by dividing that number of additional hydrogen atoms by 2. Thus IHD is $\text{10/2 = 5}$. Thus, IHD for the compound having molecular formula ${\text{C}}_{\text{6}}{\text{H}}_{\text{5}}{\text{NO}}_2$ is $\text{5}$.

Conclusion

The IHD for the compound with a given molecular formula is calculated by applying the steps above.

Interpretation Introduction

(c)

Interpretation:

IHD for the compound having the molecular formula ${\text{C}}_{\text{8}}{\text{H}}_{\text{13}}{\text{F}}_{\text{3}}\text{NO}$ is to be determined.

Concept introduction:

In order to determine the IHD of a given molecular formula, first draw any saturated molecule that has the same number of each non-hydrogen atom as in the given formula. The general formula of a saturated hydrocarbon is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$, where n stands for the number of carbon atoms. The saturated molecule must not contain double bonds, triple bonds, or rings. Each atom should have its normal number of bonds and lone pairs to avoid formal charges. Thus, each carbon should have four bonds; each hydrogen should have one bond; each oxygen should have two bonds and two lone pairs, and each halogen must have one bond and three lone pairs of electrons. The next step is to determine how many more hydrogen atoms are there in this saturated molecule compared to the formula that is given. In the last step, the IHD is calculated by dividing that number of additional hydrogen atoms by 2.

Answer to Problem 4.49P

IHD for the compound having molecular formula ${\text{C}}_{\text{8}}{\text{H}}_{\text{13}}{\text{F}}_2\text{NO}$ is $\text{2}$.

Explanation of Solution

The given molecular formula is ${\text{C}}_{\text{8}}{\text{H}}_{\text{13}}{\text{F}}_2\text{NO}$. A saturated molecule is drawn containing eight carbon atoms, one nitrogen atom, one oxygen atom, and two fluorine atoms simply by connecting all of these atoms in a row using single bonds only, as shown below:

It takes a total of $17$ hydrogen atoms to saturate each carbon, nitrogen, oxygen, and fluorine in this compound. Thus, this saturated molecule has four additional hydrogen atoms as compared to the given molecular formula. IHD for the given molecular formula is calculated by dividing that number of additional hydrogen atoms by $\text{2}$. Thus IHD is $\text{4/2 = 2}$. Thus, IHD for the compound having molecular formula ${\text{C}}_{\text{8}}{\text{H}}_{\text{13}}{\text{F}}_2\text{NO}$ is $\text{2}$.

Conclusion

The IHD for the compound with a given molecular formula is calculated by applying the steps above.

Interpretation Introduction

(d)

Interpretation:

IHD for the compound having the molecular formula ${\text{C}}_{\text{4}}{\text{H}}_{\text{12}}\text{Si}$ is to be determined.

Concept introduction:

In order to determine the IHD of a given molecular formula, first draw any saturated molecule that has the same number of each non-hydrogen atom as in the given formula. The general formula of a saturated hydrocarbon is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$, where n stands for the number of carbon atoms. The saturated molecule must not contain double bonds, triple bonds, or rings. Each atom should have its normal number of bonds and lone pairs to avoid formal charges. Thus, each carbon should have four bonds; each hydrogen should have one bond; each oxygen should have two bonds and two lone pairs, and each halogen must have one bond and three lone pairs of electrons. The next step is to determine how many more hydrogen atoms are there in this saturated molecule compared to the formula that is given. In the last step, the IHD is calculated by dividing that number of additional hydrogen atoms by 2.

Answer to Problem 4.49P

IHD for the compound having molecular formula ${\text{C}}_{\text{4}}{\text{H}}_{\text{12}}\text{Si}$ is $\text{0}$.

Explanation of Solution

The given molecular formula is ${\text{C}}_{\text{4}}{\text{H}}_{\text{12}}\text{Si}$. A saturated molecule is drawn containing four carbon atoms and one silicon atom simply by connecting all of these atoms in a row using single bonds only, as shown below:

It takes a total of $12$ hydrogen atoms to saturate each carbon and silicon atom. Thus, this saturated molecule has no additional hydrogen atoms as compared to the given molecular formula. Thus, IHD for the compound having molecular formula ${\text{C}}_{\text{4}}{\text{H}}_{\text{12}}\text{Si}$ is $\text{0}$.

Conclusion

The IHD for the compound with a given molecular formula is calculated by applying the steps above.

Interpretation Introduction

(f)

Interpretation:

IHD for the compound having the molecular formula ${\text{C}}_{\text{4}}{\text{H}}_{\text{6}}{\text{O}}_{\text{3}}\text{S}$ is to be determined.

Concept introduction:

In order to determine the IHD of a given molecular formula, first draw any saturated molecule that has the same number of each non-hydrogen atom as in the given formula. The general formula of a saturated hydrocarbon is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$, where n stands for the number of carbon atoms. The saturated molecule must not contain double bonds, triple bonds, or rings. Each atom should have its normal number of bonds and lone pairs to avoid formal charges. Thus, each carbon should have four bonds; each hydrogen should have one bond; each oxygen should have two bonds and two lone pairs, and each halogen must have one bond and three lone pairs of electrons. The next step is to determine how many more hydrogen atoms are there in this saturated molecule compared to the formula that is given. In the last step, the IHD is calculated by dividing that number of additional hydrogen atoms by 2.

Answer to Problem 4.49P

IHD for the compound having molecular formula ${\text{C}}_{\text{4}}{\text{H}}_{\text{6}}{\text{O}}_{\text{3}}\text{S}$ is $\text{2}$.

Explanation of Solution

The given molecular formula is ${\text{C}}_{\text{4}}{\text{H}}_{\text{6}}{\text{O}}_{\text{3}}\text{S}$. A saturated ion is drawn containing four carbon atoms, three oxygen atoms, and one sulfur atom simply by connecting all of these atoms in a row using single bonds only, as shown below:

It takes a total of $10$ hydrogen atoms to saturate each carbon, oxygen, and sulfur atom. Thus, this saturated molecule has $\text{4}$ additional hydrogen atoms as compared to the given molecular formula. Thus, IHD for the given molecular formula is calculated by dividing that number of additional hydrogen atoms by $\text{2}$. Thus IHD is $\text{4/2 = 2}$. Thus, IHD for the compound having molecular formula ${\text{C}}_{\text{4}}{\text{H}}_{\text{6}}{\text{O}}_{\text{3}}\text{S}$ is $2$.

Conclusion

The IHD for the compound with a given molecular formula is calculated by applying the steps above.