Chapter 1, Problem 1.94EP

(a)

Interpretation Introduction

Interpretation:

The total number of hydrogen atoms present in a cycloalkane that contains four 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.

Cycloalkanes are a class of saturated hydrocarbons that contain a ring of carbon atoms with or without alkyl substituents on it.  The general molecular formula for cycloalkanes is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.  “n” is the number of carbon atoms present.  Some of the basic examples of cycloalkanes are cyclopropane (${\text{C}}_{\text{3}}{\text{H}}_{\text{6}}$), cyclobutane (${\text{C}}_{\text{4}}{\text{H}}_8$).

Answer to Problem 1.94EP

The total number of hydrogen atoms present is 8.

Explanation of Solution

Cycloalkanes are saturated hydrocarbons that contain only single bonds between carbon atoms with a ring structure.  The general molecular formula for cycloalkane is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.  In the problem statement, the total number of carbon atoms present in the alkane is given as four.  This means that “n” is four.  This can be substituted in the general formula to obtain the total number of hydrogen atoms.

  $\begin{array}{l}{\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}\\ {\text{C}}_{\text{4}}{\text{H}}_{\left(\text{2*4}\right)}\\ {\text{C}}_{\text{4}}{\text{H}}_{\text{8}}\end{array}$

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

Conclusion

The total number of hydrogen atoms present in the cycloalkane containing four carbon atoms is eight.

(b)

Interpretation Introduction

Interpretation:

The total number of carbon atoms present in cycloalkane that contains six 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.

Cycloalkanes are a class of saturated hydrocarbons that contain a ring of carbon atoms with or without alkyl substituents on it.  The general molecular formula for cycloalkanes is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.  “n” is the number of carbon atoms present.  Some of the basic examples of cycloalkanes are cyclopropane (${\text{C}}_{\text{3}}{\text{H}}_{\text{6}}$), cyclobutane (${\text{C}}_{\text{4}}{\text{H}}_8$).

Answer to Problem 1.94EP

The total number of carbon atoms present is 3.

Explanation of Solution

Cycloalkanes are saturated hydrocarbons that contain only single bonds between carbon atoms with a ring structure.  The general molecular formula for cycloalkane is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.  In the problem statement, the total number of hydrogen atoms present in the alkane is given as six.  This means that “2n” is six.  This can be substituted in the general formula to obtain the total number of hydrogen atoms.

  $\begin{array}{l}{\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}\\ \text{2n}\text{=}\text{6}\\ \text{n}\text{=}\text{3}\end{array}$

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

Conclusion

The total number of carbon atoms present in the alkane containing six hydrogen atoms is three.

(c)

Interpretation Introduction

Interpretation:

The total number of hydrogen atoms present in cycloalkane when the total atoms present in it was 18 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.

Cycloalkanes are a class of saturated hydrocarbons that contain a ring of carbon atoms with or without alkyl substituents on it.  The general molecular formula for cycloalkanes is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.  “n” is the number of carbon atoms present.  Some of the basic examples of cycloalkanes are cyclopropane (${\text{C}}_{\text{3}}{\text{H}}_{\text{6}}$), cyclobutane (${\text{C}}_{\text{4}}{\text{H}}_8$).

Answer to Problem 1.94EP

The total number of hydrogen atoms present is 12.

Explanation of Solution

Cycloalkanes are saturated hydrocarbons that contain only single bonds between carbon atoms with no ring structure.  The general molecular formula for cycloalkane is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.  In the problem statement, the total number of atoms present in the alkane is given as 18.  This means that “n+2n” is 18.  This can be substituted in the general formula to obtain the total number of hydrogen atoms present in the given molecule.

  $\begin{array}{l}{\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}\\ \text{n+ 2n}\text{=}\text{18}\\ \text{3n}\text{=}\text{18}\\ \text{n}\text{=}\text{18/3}\\ \text{=}\text{6}\\ \text{2n}\text{=}\text{12}\end{array}$

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

Conclusion

The total number of hydrogen atoms present in the cycloalkane containing a total of 18 atoms is twelve.

(d)

Interpretation Introduction

Interpretation:

The total number of covalent bonds present in the cycloalkane that contains eight 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.

Cycloalkanes are a class of saturated hydrocarbons that contain a ring of carbon atoms with or without alkyl substituents on it.  The general molecular formula for cycloalkanes is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.  “n” is the number of carbon atoms present.  Some of the basic examples of cycloalkanes are cyclopropane (${\text{C}}_{\text{3}}{\text{H}}_{\text{6}}$), cyclobutane (${\text{C}}_{\text{4}}{\text{H}}_8$).

Answer to Problem 1.94EP

The total number of covalent bonds present is 12.

Explanation of Solution

Cycloalkanes are saturated hydrocarbons that contain only single bonds between carbon atoms with ring structure.  The general molecular formula for cycloalkane is ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$.  In the problem statement, the total number of hydrogen atoms present in the cycloalkane is given as eight.  This means that “2n” is eight.  This can be substituted in the general formula to obtain the total number of hydrogen atoms.

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

From the formula obtained for the cycloalkane, it is clear that there are eight hydrogen atoms and four 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 in a cylic fashion.  Hence, a total of 12 covalent bonds will be present in the cycloalkane that contains eight hydrogen atoms.

Conclusion

The total number of covalent bonds present in the cycloalkane that contains eight hydrogen atoms is 12.