Chapter 12, Problem 12.13EP

(a)

Interpretation Introduction

Interpretation:

The total number of hydrogen atoms present in an alkane that contains eight carbon atoms has to be identified.

Concept Introduction:

Organic compounds are the important basis of life.  They include gasoline, coal, dyes, and clothing fibers etc.  The compounds that are obtained from living organisms are termed as organic compounds and those obtained from the earth are known as inorganic compounds.  Organic compounds are found in earth also apart from living organisms.  All the organic compounds contain the element carbon.  Urea was synthesized in the laboratory which is an organic compound.

Hydrocarbons are the organic compounds that contain only hydrogen and carbon atoms.  Hydrocarbon derivatives are the one in which the compounds contain hydrogen and carbon atoms along with one or more additional elements.  The additional elements that can be present in hydrocarbon derivatives are oxygen, nitrogen, sulphur, chlorine, bromine etc.

Hydrocarbons are further classified into two categories.  They are saturated hydrocarbons and unsaturated hydrocarbons.  The hydrocarbons that contain single bonds between carbon atoms in the entire molecule is known as saturated hydrocarbon.  The hydrocarbons that contain atleast one double or triple bond between two carbon atoms in the entire molecule is known as unsaturated hydrocarbon.

Alkanes are a class of saturated hydrocarbons that do not contain a ring of carbon atoms but a chain of carbon atoms with carbon‑carbon single bonds.  The general molecular formula for alkanes is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  “n” is the number of carbon atoms present.  Some of the basic examples of alkanes are methane (${\text{CH}}_{\text{4}}$), ethane (${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}$).

Answer to Problem 12.13EP

The total number of hydrogen atoms present is 18.

Explanation of Solution

Alkanes are saturated hydrocarbons that contain only single bonds between carbon atoms with no ring structure.  The general molecular formula for alkane is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  In the problem statement, the total number of carbon atoms present in the alkane is given as eight.  This means that “n” is eight.  This can be substituted in the general formula to obtain the total number of hydrogen atoms.

  $\begin{array}{l}{\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}\\ {\text{C}}_{\text{8}}{\text{H}}_{\left(\text{2*8}\right)\text{+2}}\\ {\text{C}}_{\text{8}}{\text{H}}_{\text{18}}\end{array}$

The total number of hydrogen atoms that will be present in the given alkane is found to be eighteen.

Conclusion

The total number of hydrogen atoms present in the alkane containing eight carbon atoms is eighteen.

(b)

Interpretation Introduction

Interpretation:

The total number of carbon atoms present in an alkane that contains ten hydrogen atoms has to be identified.

Concept Introduction:

Organic compounds are the important basis of life.  They include gasoline, coal, dyes, and clothing fibers etc.  The compounds that are obtained from living organisms are termed as organic compounds and those obtained from the earth are known as inorganic compounds.  Organic compounds are found in earth also apart from living organisms.  All the organic compounds contain the element carbon.  Urea was synthesized in the laboratory which is an organic compound.

Hydrocarbons are the organic compounds that contain only hydrogen and carbon atoms.  Hydrocarbon derivatives are the one in which the compounds contain hydrogen and carbon atoms along with one or more additional elements.  The additional elements that can be present in hydrocarbon derivatives are oxygen, nitrogen, sulphur, chlorine, bromine etc.

Hydrocarbons are further classified into two categories.  They are saturated hydrocarbons and unsaturated hydrocarbons.  The hydrocarbons that contain single bonds between carbon atoms in the entire molecule is known as saturated hydrocarbon.  The hydrocarbons that contain atleast one double or triple bond between two carbon atoms in the entire molecule is known as unsaturated hydrocarbon.

Alkanes are a class of saturated hydrocarbons that do not contain a ring of carbon atoms but a chain of carbon atoms with carbon‑carbon single bonds.  The general molecular formula for alkanes is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  “n” is the number of carbon atoms present.  Some of the basic examples of alkanes are methane (${\text{CH}}_{\text{4}}$), ethane (${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}$).

Answer to Problem 12.13EP

The total number of carbon atoms present is 4.

Explanation of Solution

Alkanes are saturated hydrocarbons that contain only single bonds between carbon atoms with no ring structure.  The general molecular formula for alkane is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  In the problem statement, the total number of hydrogen atoms present in the alkane is given as ten.  This means that “2n+2” is ten.  This can be substituted in the general formula to obtain the total number of carbon atoms.

  $\begin{array}{l}{\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}\\ \text{2n+2}\text{=}\text{10}\\ \text{2n}\text{=}\text{8}\\ \text{n}\text{=}\text{8/2}\\ \text{=}\text{4}\end{array}$

The total number of carbon atoms that will be present in the given alkane is found to be four.

Conclusion

The total number of carbon atoms present in the alkane containing ten hydrogen atoms is four.

(c)

Interpretation Introduction

Interpretation:

The total number of carbon atoms present in an alkane when the total atoms present in it was 41 has to be identified.

Concept Introduction:

Organic compounds are the important basis of life.  They include gasoline, coal, dyes, and clothing fibers etc.  The compounds that are obtained from living organisms are termed as organic compounds and those obtained from the earth are known as inorganic compounds.  Organic compounds are found in earth also apart from living organisms.  All the organic compounds contain the element carbon.  Urea was synthesized in the laboratory which is an organic compound.

Hydrocarbons are the organic compounds that contain only hydrogen and carbon atoms.  Hydrocarbon derivatives are the one in which the compounds contain hydrogen and carbon atoms along with one or more additional elements.  The additional elements that can be present in hydrocarbon derivatives are oxygen, nitrogen, sulphur, chlorine, bromine etc.

Hydrocarbons are further classified into two categories.  They are saturated hydrocarbons and unsaturated hydrocarbons.  The hydrocarbons that contain single bonds between carbon atoms in the entire molecule is known as saturated hydrocarbon.  The hydrocarbons that contain atleast one double or triple bond between two carbon atoms in the entire molecule is known as unsaturated hydrocarbon.

Alkanes are a class of saturated hydrocarbons that do not contain a ring of carbon atoms but a chain of carbon atoms with carbon‑carbon single bonds.  The general molecular formula for alkanes is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  “n” is the number of carbon atoms present.  Some of the basic examples of alkanes are methane (${\text{CH}}_{\text{4}}$), ethane (${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}$).

Answer to Problem 12.13EP

The total number of carbon atoms present is 13.

Explanation of Solution

Alkanes are saturated hydrocarbons that contain only single bonds between carbon atoms with no ring structure.  The general molecular formula for alkane is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  In the problem statement, the total number of atoms present in the alkane is given as 41.  This means that “n+2n+2” is 41.  This can be substituted in the general formula to obtain the total number of carbon atoms present in the given molecule.

  $\begin{array}{l}{\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}\\ \text{n+ 2n}\text{+}\text{2}\text{=}\text{41}\\ \text{3n}\text{+}\text{2}\text{=}\text{41}\\ \text{3n}\text{=}\text{39}\\ \text{n}\text{=}\text{39/3}\\ \text{=}\text{13}\end{array}$

The total number of carbon atoms that will be present in the given alkane is found to be thirteen.

Conclusion

The total number of carbon atoms present in the alkane containing a total of 41 atoms is thirteen.

(d)

Interpretation Introduction

Interpretation:

The total number of covalent bonds present in the alkane that contains seven carbon atoms has to be identified.

Concept Introduction:

Organic compounds are the important basis of life.  They include gasoline, coal, dyes, and clothing fibers etc.  The compounds that are obtained from living organisms are termed as organic compounds and those obtained from the earth are known as inorganic compounds.  Organic compounds are found in earth also apart from living organisms.  All the organic compounds contain the element carbon.  Urea was synthesized in the laboratory which is an organic compound.

Hydrocarbons are the organic compounds that contain only hydrogen and carbon atoms.  Hydrocarbon derivatives are the one in which the compounds contain hydrogen and carbon atoms along with one or more additional elements.  The additional elements that can be present in hydrocarbon derivatives are oxygen, nitrogen, sulphur, chlorine, bromine etc.

Hydrocarbons are further classified into two categories.  They are saturated hydrocarbons and unsaturated hydrocarbons.  The hydrocarbons that contain single bonds between carbon atoms in the entire molecule is known as saturated hydrocarbon.  The hydrocarbons that contain atleast one double or triple bond between two carbon atoms in the entire molecule is known as unsaturated hydrocarbon.

Alkanes are a class of saturated hydrocarbons that do not contain a ring of carbon atoms but a chain of carbon atoms with carbon‑carbon single bonds.  The general molecular formula for alkanes is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  “n” is the number of carbon atoms present.  Some of the basic examples of alkanes are methane (${\text{CH}}_{\text{4}}$), ethane (${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}$).

Answer to Problem 12.13EP

The total number of covalent bonds present is 22.

Explanation of Solution

Alkanes are saturated hydrocarbons that contain only single bonds between carbon atoms with no ring structure.  The general molecular formula for alkane is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}$.  In the problem statement, the total number of carbon atoms present in the alkane is given as seven.  This means that “n” is seven.  This can be substituted in the general formula to obtain the total number of hydrogen atoms.

  $\begin{array}{l}{\text{C}}_{\text{n}}{\text{H}}_{\text{2n+2}}\\ {\text{C}}_{\text{7}}{\text{H}}_{\left(\text{2*7}\right)\text{+2}}\\ {\text{C}}_{\text{7}}{\text{H}}_{\text{16}}\end{array}$

From the formula obtained for the alkane, it is clear that there are sixteen hydrogen atoms and six carbon atoms.  Each hydrogen atom will be bonded to carbon atom through a covalent bond.  Each carbon atom will be bonded to other carbon atom through a covalent bond.  Hence, a total of 22 covalent bonds will be present in the alkane that contains seven carbon atoms.

Conclusion

The total number of covalent bonds present in the alkane that contains seven carbon atoms is 22.