Chapter 21, Problem 95E

Distinguish precisely, and in scientific terms, the differences among items in each of the following pairs or groups.

a) Organic chemistry, inorganic chemistry

b) Saturated and unsaturated hydrocarbons

c) Alkanes, alkenes, alkynes

d) Normal alkane, branched alkane

e) Cis and trans isomers

f) Structural formula, condensed (line) formula, molecular formula

g) Addition reaction, substitution reaction

h) Alkane, alkyl group

i) Monomer, polymer

j) Aliphatic hydrocarbon, aromatic hydrocarbon

k) Ortho-, meta-, para

l) Alcohol, aldehyde, carboxylic acid

m) Hydroxyl group, carbonyl group, carboxyl group

n) Primary, secondary, tertiary alcohols

o) Alcohol, ether

p) Aldehyde, ketone

q) Carboxylic acid, ester

r) Carboxylic acid, amide

s) Amine, amide

t) Primary, secondary, tertiary amine

u) Chain-growth polymer, step-growth polymer

Interpretation Introduction

(a)

Interpretation:

The difference between organic chemistry and inorganic chemistry is to be determined.

Concept introduction:

The compound is a substance that consists of the atoms connected to each other by chemical bonds. Compounds can be classified as organic and inorganic material on the basis of the material from which they are derived. The organic chemistry deals with the compounds that are obtained from plants, animals and living organisms and inorganic chemistry deals with the compounds that are obtained from minerals.

Answer to Problem 95E

The chemistry of minerals and the compounds derived from the minerals is known as inorganic chemistry.

The chemistry of the compounds that deals with the compounds that are derived from plants, animals and living organisms is known as organic chemistry. It can also be defined as the chemistry that deals with carbon compounds.

Explanation of Solution

Compounds can be classified as organic and inorganic material on the basis of the material from which they are derived.

The organic compound is the class of compound that has carbon-hydrogen bond or carbon-carbon long chains in their structure. They are derived from plants, animals and living organisms. For example, acetate ion $\left({\text{C}}_2{\text{H}}_3{\text{O}}_2^{3-}\right)$ is an organic ion because it has a carbon-hydrogen bond in its structure. The structure of acetate ion $\left({\text{C}}_2{\text{H}}_3{\text{O}}_2^{3-}\right)$ is,

Inorganic compounds are those compounds that consist of other elements than carbon or have no carbon-carbon bond in their structure. They are derived from minerals. Cyanide ion $\left({\text{CN}}^{-}\right)$ and carbonate ion $\left({\text{CO}}_3^{2-}\right)$ are considered as inorganic ion because they do not consist of carbon-hydrogen bond in their structure.

Conclusion

The chemistry of minerals and the compounds derived from the minerals is known as inorganic chemistry.

The chemistry of the compounds that deals with the compounds that are derived from plants, animals and living organisms is known as organic chemistry. It can also be defined as the chemistry that deals with carbon compounds.

Interpretation Introduction

(b)

Interpretation:

The difference between saturated and unsaturated hydrocarbons is to be determined.

Concept introduction:

Hydrocarbons are the binary compounds that consist of carbon and hydrogen atoms in its structure. Hydrocarbons can be classified into two types: saturated hydrocarbon and unsaturated hydrocarbon.

Saturated hydrocarbon consists of single bonds in its structure and unsaturated hydrocarbon consists of double or triple bond in its structure.

Answer to Problem 95E

Saturated hydrocarbons are those in which carbon atom is singly-bonded to other 4 other atoms. Unsaturated hydrocarbons consist of double or triple C-C bond in its structure.

Explanation of Solution

Hydrocarbons can be classified into two types: saturated hydrocarbon and unsaturated hydrocarbon.

Saturated hydrocarbons are those in which each carbon atom is singly-bonded to four other atoms in the structure. Alkanes are an example of saturated hydrocarbons. In alkanes, each carbon atom is bonded four other atoms via single bond only. The general formula of alkanes is ${\text{C}}_n{\text{H}}_{2n+2}$, $n$ is the number of carbon atoms. For example, methane $\left({\text{CH}}_{\text{4}}\right)$ and ethane $\left({\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\right)$.

Unsaturated hydrocarbons consist of double or triple carbon-carbon bond in its structure and less than the maximum bond that carbon can make. Alkenes and alkynes are examples of an unsaturated hydrocarbon. Alkenes consist of a carbon-carbon double bond in its structure and alkynes consist of carbon-carbon triple bond in its structure. For example, ethene $\left({\text{C}}_2{\text{H}}_4\right)$ and ethyne $\left({\text{C}}_2{\text{H}}_2\right)$.

Conclusion

Saturated hydrocarbons are those in which carbon atom is singly-bonded to other 4 other atoms. Unsaturated hydrocarbons consist of double or triple C-C bond in its structure.

Interpretation Introduction

(c)

Interpretation:

The difference between alkanes, alkenes, alkynes is to be determined.

Concept introduction:

Hydrocarbons are the binary compounds consist of carbon and hydrogen atoms in its structure. Alkanes, alkenes, and alkynes are examples of hydrocarbons.

Alkanes consist of a single bond, alkenes consist of double bond and alkynes consist of triple bond in its structure.

Answer to Problem 95E

Alkanes are the saturated hydrocarbons in which carbon atom is bonded to four other carbon atoms by a single bond. An alkene is a class of hydrocarbon that contains one C=C bond between two carbons. An alkyne is a class of hydrocarbon that contains a triple bond between C-C.

Explanation of Solution

Alkanes are the saturated hydrocarbons in which each carbon atom is bonded to four other atoms via single bond only. The general formula of alkanes is ${\text{C}}_n{\text{H}}_{2n+2}$, $n$ is the number of carbon atoms. For example, ethane.

The structure of ethane is,

Alkenes are the unsaturated hydrocarbons that contain at least the one double bond between two carbons atoms. The general formula of alkenes is ${\text{C}}_n{\text{H}}_{2n}$. For example, ethene. The structure of ethene is,

Alkynes are the unsaturated hydrocarbons that contain at least the one triple bond between two carbons atoms. The general formula of alkenes is ${\text{C}}_n{\text{H}}_{2n-2}$. For example, ethyne. The structure of ethyne is,

Conclusion

Alkanes are the saturated hydrocarbons in which each carbon atom is bonded to four other atoms via single bond only. An alkene is a class of hydrocarbon that contains at least the one double bond between two carbons. An alkyne is a class of hydrocarbon that contains at least the one triple bond between two carbons.

Interpretation Introduction

(d)

Interpretation:

The difference between normal alkane and branched alkane is to be determined.

Concept introduction:

Hydrocarbons are the binary compounds that consist of carbon and hydrogen atoms in its structure.

Alkanes are the saturated hydrocarbons in which each carbon atom is bonded to four other atoms via single bond only. The general formula of alkanes is ${\text{C}}_n{\text{H}}_{2n+2}$, $n$ is the number of carbon atoms. Alkanes can be classified as normal alkane and branched alkane.

Normal alkanes are the alkanes that have a straight chain in their structure and branched alkanes are obtained by the substitution of alkyl group in place of a hydrogen atom in a normal alkane.

Answer to Problem 95E

If all the carbon atoms in alkane are arranged in a linear or continuous chain, the resulting hydrocarbon is called normal alkane. If all the carbon atoms in alkane are not arranged in a linear or continuous chain, the resulting hydrocarbon is called branched alkane.

Explanation of Solution

If all the carbon atoms in alkane are arranged in a linear or continuous chain, the resulting hydrocarbon is called normal alkane. Normal alkanes are also known as straight chain alkanes. The structural formula of a normal alkane is as follows,

Branched alkanes are derived from the normal alkanes by substituting one or more hydrogen atom with an alkyl group.

The structural formula of a branched alkane is as follows,

Conclusion

If all the carbon atoms in alkane are arranged in a linear or continuous chain, the resulting hydrocarbon is called normal alkane. If all the carbon atoms in alkane are not arranged in a linear or continuous chain, the resulting hydrocarbon is called branched alkane.

Interpretation Introduction

(e)

Interpretation:

The difference between cis and trans isomers is to be determined.

Concept introduction:

Isomers are the compounds which have the same molecular formula but a different arrangement of atoms. Alkenes have a double bond between carbon atoms. Due to the presence of a double bond, the rotation about adjacent carbon-carbon atoms is highly restricted. Hence, alkenes can exist in two forms: cis and trans isomers. In alkenes, when the two same groups are on the same side of the double bond then is known as cis-isomer and when the two same groups are on the opposite side of the double bond then is known trans-isomer.

Answer to Problem 95E

Cis isomer is the one in which the identical groups are placed on the same side of the double bond and trans isomer is the one in which the identical groups are placed on the different side of the double bond.

Explanation of Solution

An alkene is a molecule that contains at least the one double bond between two carbons atoms. Due to the presence of a double bond, the rotation about adjacent carbon-carbon atoms is highly restricted. Hence, alkenes can exist in two forms which have the same molecular formula but a different arrangement of atoms around the double bond. This isomerism is a type of stereoisomerism which is known as geometric isomerism or cis-trans isomerism, for example, 1, 2-dichloroethane can show the geometrical isomerism,

Conclusion

Cis isomer is the one in which the identical groups are placed on the same side of the double bond and trans isomer is the one in which the identical groups are placed on the different side of the double bond.

Interpretation Introduction

(f)

Interpretation:

The difference between structural formula, condensed (line) formula, the molecular formula is to be determined.

Concept introduction:

A hydrocarbon can be represented using different formulas. It can be represented using structural formula, structural diagram, line formula, condensed formula, or Lewis diagram.

Answer to Problem 95E

Structural formula represents the arrangement and bonding between the atoms without representing the unshared pairs of electrons. Line formula is the shorthand representation of the Lewis diagram, in which the bond between the parent chain carbon and atoms or other branches from the chain are not shown. Clubbing of ${\text{CH}}_{\text{2}}$ units together in a line formula gives condensed formula. Molecular formula represents the number of atoms of each element present in the compound.

Explanation of Solution

The molecular formula is the simplest representation of the compound that tells about the number of atoms of each element present in the compound. Therefore, the molecular formula of an alkane having 7 carbon atoms is ${\text{C}}_{\text{7}}{\text{H}}_{\text{16}}$.

In line formula, the bond between the chain carbon and atoms or other branches from the chain is not shown. It is the shorthand representation of the Lewis diagram of the molecule or compound. Therefore, the line formula of an alkane having 7 carbon atoms is ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}$.

The condensed formula is the formula in which the ${\text{CH}}_{\text{2}}$ in a line formula are club together. In alkane having 7 carbon atoms, five ${\text{CH}}_{\text{2}}$ units are present. In the condensed formula, unlike line formula, all the five ${\text{CH}}_{\text{2}}$ units are grouped together. Therefore, the condensed formula is ${\text{CH}}_{\text{3}}{\left({\text{CH}}_{\text{2}}\right)}_{\text{5}}{\text{CH}}_{\text{3}}$.

Structural formula represents the arrangement and bonding between the atoms without representing the unshared pairs of electrons. In alkanes, all the carbon atoms are bonded to four different atoms. Therefore, the structural formula is,

Conclusion

Structural formula represents the arrangement and bonding between the atoms without representing the unshared pairs of electrons. Line formula is the shorthand representation of the Lewis diagram, in which the bond between the parent chain carbon and atoms or other branches from the chain are not shown. Clubbing of ${\text{CH}}_{\text{2}}$ units together in a line formula gives condensed formula. Molecular formula represents the number of atoms of each element present in the compound.

Interpretation Introduction

(g)

Interpretation:

The difference between the addition reaction and substitution reaction is to be determined.

Concept introduction:

Addition reaction involves the formation of a large molecule by the reaction of two molecules whereas substitution reaction involves the replacement of hydrogen atom by the other atom or group.

Answer to Problem 95E

In the addition reaction, two atoms are added on both sides of the multiple bonds.

In the substitution reaction, one or more hydrogen atoms from the reactant molecule are substituted by one or more other atoms or groups.

Explanation of Solution

An addition reaction is a reaction in which two molecules react to form one larger molecule. Unsaturated hydrocarbons (alkenes and alkynes) have carbon-carbon multiple bonds and thus undergo addition reaction. Alkenes and alkynes are capable of adding atoms of a molecule across the carbon-carbon double or triple bond respectively and give corresponding alkanes.

For example:

Alkanes give substitution reactions. In the substitution reaction, one or more hydrogen atoms from alkanes are substituted by one or more other atoms or groups in presence of heat and light. An example of a substitution reaction of alkanes is as follows:

Conclusion

In the addition reaction, two atoms are added on both sides of the multiple bonds.

In the substitution reaction, one or more hydrogen atoms from the reactant molecule are substituted by one or more other atoms or groups.

Interpretation Introduction

(h)

Interpretation:

The difference between alkane and alkyl group is to be determined.

Concept introduction:

Hydrocarbons are the binary compounds that consist of carbon and hydrogen atoms in its structure.

Alkanes are the saturated hydrocarbons in which each carbon atom is bonded to four other atoms via single bond only. Alkyl group is derived from an alkane. It is an alkane with one hydrogen atom less than the corresponding alkane.

Answer to Problem 95E

An alkyl group is derived from the corresponding alkane. The general formula of an alkane is ${\text{C}}_n{\text{H}}_{2n+2}$ and the general formula of alkyl can be considered as ${\text{C}}_n{\text{H}}_{2n+1}$.

Explanation of Solution

An alkyl group is derived from the corresponding alkane. Alkyl group is an alkane with one hydrogen atom less than the corresponding alkane. The alkyl group is named as the name of the alkane counterpart containing the same number of carbon atoms by replacing the suffix “ane” in the name with “yl”.

The molecular formula of an alkane with two carbon atoms is ${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}$ and the molecular formula of the corresponding alkyl group is $-{\text{C}}_{\text{2}}{\text{H}}_{\text{5}}$.

The name of an alkane with two carbon atoms is ethane and the name of the alkyl group is ethyl.

Conclusion

An alkyl group is derived from the corresponding alkane. The general formula of an alkane is ${\text{C}}_n{\text{H}}_{2n+2}$ and the general formula of alkyl can be considered as ${\text{C}}_n{\text{H}}_{2n+1}$.

Interpretation Introduction

(i)

Interpretation:

The difference between monomer and polymer is to be determined.

Concept introduction:

Polymers are the macromolecules that are formed by the repeating monomeric units known as monomers.

Answer to Problem 95E

Monomers are small molecules that combine together in a sequential manner to produce a large molecule called polymer.

Explanation of Solution

Polymers are large compounds formed by polymerization of a number of repeated molecules called monomers. They are formed when the monomers are linked to one another by a suitable reaction like addition reaction or condensation reaction.

Conclusion

Monomers are small molecules that combine together in a sequential manner to produce a large molecule called polymer.

Interpretation Introduction

(j)

Interpretation:

The difference between aliphatic hydrocarbon and aromatic hydrocarbon is to be determined.

Concept introduction:

Hydrocarbons are the binary compounds that consist of carbon and hydrogen atoms in its structure. Aliphatic hydrocarbons are organic compounds that have open chain like structure and aromatic hydrocarbon have ring like structure with an alternate single and double bond in their structure.

Answer to Problem 95E

Aliphatic hydrocarbons are organic compounds in which carbon and hydrogen are bonded in the open chain or non-aromatic rings. Aliphatic hydrocarbons do not contain benzene ring in its structure. Aromatic hydrocarbons are cyclic compounds that contain the alternate single and double bond or benzene ring in its structure.

Explanation of Solution

Alkanes are an example of open chain aliphatic hydrocarbons and cycloalkanes are an example of closed or ring aliphatic hydrocarbons. Most of the alkanes exist in an open-chain for example:

Benzene is the simplest aromatic hydrocarbon and thus aromatic hydrocarbons are also defined as the compounds that contain benzene in its structure. The structure of benzene is,

Conclusion

Aliphatic hydrocarbons are organic compounds in which carbon and hydrogen are bonded in the open chain or non-aromatic rings. Aliphatic hydrocarbons do not contain benzene ring in its structure. Aromatic hydrocarbons are cyclic compounds that contain the alternate single and double bond or benzene ring in its structure.

Interpretation Introduction

(k)

Interpretation:

The difference between ortho-, meta-, -para is to be determined.

Concept introduction:

Aromatic hydrocarbons exhibit aromaticity. Aromaticity is a property exhibited by conjugated cycloalkenes in which the stability is gained by the delocalization of the electrons in the pi-orbitals. Aromatic hydrocarbons contain one or more benzene rings. Benzene is the simplest aromatic hydrocarbon. Those hydrocarbons which do not contain a benzene ring are called aliphatic hydrocarbons.

Answer to Problem 95E

Ortho-, meta- and para- are prefixes used to denote the position of the substituent when two hydrogens of the benzene ring are substituted. If two hydrogens are substitute two adjacent hydrogen atoms the name of the compound is given by using the prefix ortho. If two hydrogens are substitute two hydrogen atoms attached to 1 and 3 carbon atom the name of the compound is given by using the prefix meta. If two hydrogens are substitute two hydrogen atoms attached to 1 and 4 carbon atom the name of the compound is given by using the prefix para.

Explanation of Solution

Benzene is the simplest aromatic hydrocarbon. The structure of benzene and the relative positions with respect to substituent X are as follows:

Xylene is the common name for dimethylbenzene. There are three isomers possible for xylene depending upon the position of the two methyl groups attached to the benzene ring are $\text{ortho-dimethylbenzene}$, $\text{meta-dimethylbenzene}$ and $\text{para-dimethylbenzene}$.

Conclusion

Ortho-, meta- and para- are prefixes used to denote the position of the substituent when two hydrogen of the benzene ring are substituted. If two hydrogens are substitute two adjacent hydrogen atoms the name of the compound is given by using the prefix ortho. If two hydrogen are substitute two hydrogen atoms attached to 1 and 3 carbon atom the name of the compound is given by using the prefix meta. If two hydrogens are substitute two hydrogen atoms attached to 1 and 4 carbon atom the name of the compound is given by using the prefix para.

Interpretation Introduction

(l)

Interpretation:

The difference between alcohol, aldehyde, and carboxylic acid is to be determined.

Concept introduction:

Concept introduction:

The properties of the compound are largely governed by the functional group present in the compound. The general representation of alcohol, aldehyde, and the carboxylic acid is $\text{R}-\text{OH}$, $\text{R}-\text{CHO}$ and $\text{R}-\text{COOH}$ respectively. Here, $\text{R}$ is an alkyl group.

Answer to Problem 95E

The functional group determines the class of the compound to which it belongs. The properties of the compound are largely governed by the functional group present in the compound. Different functional groups have different characteristic properties.

Functional groups	Structures
Alcohol
Aldehyde
Carboxylic acid

Explanation of Solution

Alcohol is a functional group which contains a hydroxyl group. The oxygen atom of the hydroxyl group is attached to the alkyl group via a single bond. Hydroxy group is obtained by removal of one hydrogen atom from the water molecule. Substitution of one hydrogen atom from the water by an alkyl group $\left(-\text{R}\right)$ forms an alcohol functional group.

An aldehyde is a functional group in which the carbonyl group is attached to the hydrogen atom on one side and alkyl group on another side.

A carboxyl group is a functional group containing a carbonyl group attached to a hydroxyl group via a single bond. A carboxyl group attached to an alkyl group forms a carboxylic acid.

Conclusion

The functional group determines the class of the compound to which it belongs. The properties of the compound are largely governed by the functional group present in the compound. Different functional groups have different characteristic properties.

Functional groups	Structures
Alcohol
Aldehyde
Carboxylic acid

Interpretation Introduction

(m)

Interpretation:

The difference between the hydroxyl group, a carbonyl group, and a carboxyl group is to be determined.

Concept introduction:

The properties of the compound are largely governed by the functional group present in the compound. Hydroxyl group is present in alcohol, the carbonyl group in aldehyde or ketone and a carboxyl group in a carboxylic acid.

Answer to Problem 95E

The functional group determines the class of the compound to which it belongs. The properties of the compound are largely governed by the functional group present in the compound. Different functional groups have different characteristic properties.

Functional groups	Identifies as	Structures
Hydroxyl	Alcohol
Carbonyl	Aldehyde or ketone
Carboxyl	Carboxylic acid

Explanation of Solution

A hydroxyl group is a functional group in which oxygen atom is bonded to a hydrogen atom via a single bond. Hydroxy group is obtained by removal of one hydrogen atom from the water molecule.

A carbonyl group is a functional group in which carbon is bonded to oxygen by a double bond.

A carboxyl group is a functional group containing a carbonyl group attached to a hydroxyl group via a single bond.

Conclusion

The functional group determines the class of the compound to which it belongs. The properties of the compound are largely governed by the functional group present in the compound. Different functional groups have different characteristic properties.

Functional groups	Identifies as	Structures
Hydroxyl	Alcohol
Carbonyl	Aldehyde or ketone
Carboxyl	Carboxylic acid

Interpretation Introduction

(n)

Interpretation:

The difference between primary, secondary, and tertiary alcohols is to be determined.

Concept Introduction:

Alcohols are organic compounds containing a $-\text{OH}$ group. They are named from the parent alkane by dropping the “-e” from the end of the alkane and replacing it with an “-ol”. Polyhydric alcohols have more than one $-\text{OH}$ group and are named diol for 2 and triol for 3. Alcohols form hydrogen bonds and hence have a much higher boiling point than their corresponding alkanes.

Answer to Problem 95E

(1) Primary alcohols: Alcohol in which the hydroxyl group is attached to the primary carbon atom is called primary alcohol.

(2) Secondary alcohols: Alcohol in which the hydroxyl group is attached to the secondary carbon atom is called secondary alcohol.

(3) Tertiary alcohols: Alcohol in which the hydroxyl group is attached to the tertiary carbon atom is called tertiary alcohol.

Explanation of Solution

Alcohol is a functional group which contains a hydroxyl group. The oxygen atom of the hydroxyl group is attached to the alkyl group via a single bond. Hydroxy group is obtained by removal of one hydrogen atom from the water molecule. Substitution of one hydrogen atom from the water by an alkyl group $\left(-\text{R}\right)$ forms an alcohol functional group.

A tertiary carbon $\left(3°\right)$ is the one which is attached to three carbon atoms in the molecule.

A secondary carbon $\left(2°\right)$ is the one which is attached to two carbon atoms in the molecule.

A primary carbon $\left(1°\right)$ is the one which is attached to one carbon atom in the molecule.

The structural formula of primary alcohol, secondary and tertiary alcohol is,

Conclusion

Primary alcohols: Alcohol in which the hydroxyl group is attached to the primary carbon atom is called primary alcohol. Secondary alcohols: Alcohol in which the hydroxyl group is attached to the secondary carbon atom is called secondary alcohol. Tertiary alcohols: Alcohol in which the hydroxyl group is attached to the tertiary carbon atom is called tertiary alcohol.

Interpretation Introduction

(o)

Interpretation:

The difference between alcohol and ether is to be determined.

Concept Introduction:

Alcohols are organic compounds containing a $-\text{OH}$ group. They are named from the parent alkane by dropping the “-e” from the end of the alkane and replacing it with an “-ol”. Polyhydric alcohols have more than one $-\text{OH}$ group and are named diol for 2 and triol for 3. Alcohols form hydrogen bonds and hence have a much higher boiling point than their corresponding alkanes.

Ethers are organic compounds containing an oxygen atom intervened between two alkyl groups. Ethers are derived from alkanes by replacing a hydrogen atom for an alkoxy group. The structure of ethers is not held together by hydrogen bonds. Due to very low polarity, ethers are not very well soluble in water.

Answer to Problem 95E

Alcohols and ethers both have the same general formula ${\text{C}}_n{\text{H}}_{2n}\text{O}$ but have different structural formulas. Alcohol has $-\text{OH}$ group while ether has oxo $\left(\text{R}-\text{O}-\text{R'}\right)$ linkages between two alkyl groups.

Explanation of Solution

Alcohol is an organic compound in which a hydroxyl group is attached to the carbon chain. The general representation of alcohol is $\text{R}-\text{OH}$, $\text{R}$ represents an alkyl group. Ethanol is an example of alcohol. The molecular formula of ethanol is ${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\text{O}$.

Ether is an organic compound in which oxygen atom is attached with two alkyl groups. The general representation of ether is $\text{R}-\text{O}-{\text{R}}^{\text{'}}$, $\text{R}$ and ${\text{R}}^{\text{'}}$ represents the alkyl group that can be the same or different. Dimethyl ether is an example of ether. The molecular formula of dimethyl ether is also ${\text{C}}_{\text{2}}{\text{H}}_{\text{6}}\text{O}$.

Conclusion

Alcohols and ethers both have the same general formula ${\text{C}}_n{\text{H}}_{2n}\text{O}$ but have different structural formulas. Alcohol has $-\text{OH}$ group while ether has oxo $\left(\text{R}-\text{O}-\text{R'}\right)$ linkages between two alkyl groups.

Interpretation Introduction

(p)

Interpretation:

The difference between aldehyde and ketone is to be determined.

Concept Introduction:

Aldehydes are organic compounds containing a $\text{-CHO}$ functional group. The carbon atom is bonded to the oxygen atom through a double bond. Hence aldehydes are carbonyl compounds. Aldehydes easily oxidize to give carboxylic acids.

Ketones are organic compounds in which two alkyl/aryl groups are intervened by a $\text{-CO}$ carbonyl group. Hence ketones are also carbonyl compounds. Ketones can only be oxidized by strong oxidizing agents.

Answer to Problem 95E

Aldehyde and ketone both have carbonyl group but in ketone, the carbonyl group is attached to the alkyl group on either side whereas in aldehyde it is attached to the hydrogen atom on one side and to alkyl group on another side.

Explanation of Solution

Aldehyde and ketones are characterized by the carbonyl group. If the carbonyl group is attached to the hydrogen atom on one side and to an alkyl group on the other side the compound formed is called aldehyde and if an alkyl group is attached to either side of the carbonyl group the compound formed is called ketone.

Conclusion

Aldehyde and ketone both have carbonyl group but in ketone, the carbonyl group is attached to the alkyl group on either side whereas in aldehyde it is attached to the hydrogen atom on one side and to alkyl group on another side.

Interpretation Introduction

(q)

Interpretation:

The difference between carboxylic acid and ester is to be determined.

Concept Introduction:

Esters are derivatives of carboxylic acids. Esters are more polar than ethers but less polar than alcohols. There is no intra-molecular hydrogen bonding in esters and hence their boiling points are significantly lower than those of acid with the same number of carbon atoms. Esters have pleasant odors and give a characteristic smell to fruits and flowers.

Carboxylic acids are compounds characterized by the presence of a $\text{-COOH}$ group at the end of the chain. Due to the presence of the hydroxyl in the carboxyl group, carboxylic acids are polar in nature. This also facilitates their solubility in water. However, as the size of the molecules increases, the solubility decreases due to the increase in the hydrocarbon chain length which is hydrophobic in nature.

Answer to Problem 95E

The carboxylic acid is an organic acid that contains carbonyl group attached to a hydroxyl group whereas in ester the carbonyl group is attached to an alkyl group.

Explanation of Solution

The carboxylic acid consists of the carboxyl group in its structure that is bonded to the alkyl group. The general representation of carboxylic acid is,

Ester also consists of a carboxyl group in its structure. In ester, the carboxyl carbon can be bonded to hydrogen or alkyl group but the oxygen of the carboxyl group must be bonded to an alkyl group. The general representation of ester is,

Conclusion

The carboxylic acid is an organic acid that contains carbonyl group attached to a hydroxyl group whereas in ester the carbonyl group is attached to an alkyl group.

Interpretation Introduction

(r)

Interpretation:

The difference between carboxylic acid and amide is to be determined.

Concept Introduction:

Carboxylic acids are compounds characterized by the presence of a $\text{-COOH}$ group at the end of the chain. Due to the presence of the hydroxyl in the carboxyl group, carboxylic acids are polar in nature. This also facilitates their solubility in water. However, as the size of the molecules increases, the solubility decreases due to the increase in the hydrocarbon chain length which is hydrophobic in nature.

Amides are organic compounds represented as ${\text{RCONH}}_2$. Amides are derived from carboxylic acids. Amides have the ability to form hydrogen bonds and hence they are soluble in water. This also imparts higher melting points for their molecular size Unlike amines, amides do not show appreciable basicity, hence they are not basic in nature.

Answer to Problem 95E

The carboxylic acid is an organic acid that contains carbonyl group attached to a hydroxyl group whereas in amide the carbonyl group is attached to an amine group.

Explanation of Solution

The carboxylic acid consists of the carboxyl group in its structure that is bonded to the alkyl group. The general representation of carboxylic acid is,

Amides are the derivatives of carboxylic acids in which the hydroxyl group is replaced by an amine. The structure of the corresponding amide group is,

Conclusion

The carboxylic acid is an organic acid that contains carbonyl group attached to a hydroxyl group whereas in amide the carbonyl group is attached to an amine group.

Interpretation Introduction

(s)

Interpretation:

The difference between amine and amide is to be determined.

Concept Introduction:

Amines are compounds which contain a base nitrogen atom with a lone pair. The lower aliphatic amines are gaseous in nature. Lower aliphatic amines can form hydrogen bonds with water molecules. Hence such amines are water soluble. As the number of alkyl groups increases in the amines, their hydrophobic nature increases as well and hence, the solubility in water decreases. Amides are organic compounds represented as ${\text{RCONH}}_2$. Amides are derived from carboxylic acids. Amides have the ability to form hydrogen bonds and hence they are soluble in water. This also imparts higher melting points for their molecular size Unlike amines, amides do not show appreciable basicity, hence they are not basic in nature.

Answer to Problem 95E

In amines, the nitrogen atom is attached to the one, two, or three alkyl group whereas in amides the nitrogen atom is attached to a carbonyl group. Also, amines are derivative of ammonia and amides are derivative of carboxylic acid.

Explanation of Solution

The nitrogen-containing organic compounds are known as amines. They are derivatives of ammonia. Substitution of one, two or three hydrogen atoms in the ammonia molecule by an alkyl group form an amine. Amines can be classified as primary, secondary or tertiary depending upon how many alkyl groups are attached to the nitrogen atom in amines.

Amides are the derivatives of carboxylic acids in which the hydroxyl group is replaced by an amine. The structure of the corresponding amide group is,

Conclusion

In amines, the nitrogen atom is attached to the one, two, or three alkyl group whereas in amides the nitrogen atom is attached to a carbonyl group. Also, amines are derivative of ammonia and amides are derivative of carboxylic acid.

Interpretation Introduction

(t)

Interpretation:

The difference between primary, secondary, and tertiary amine is to be determined.

Concept Introduction:

Amines are compounds which contain a base nitrogen atom with a lone pair. The lower aliphatic amines are gaseous in nature. Lower aliphatic amines can form hydrogen bonds with water molecules. Hence such amines are water soluble. As the number of alkyl groups increases in the amines, their hydrophobic nature increases as well and hence, the solubility in water decreases. Primary and secondary amines are often engaged in the intermolecular association as a result of hydrogen bonding between the nitrogen of one and hydrogen of another molecule. In tertiary amines, there is no such association. Hence the order of boiling points of amines follows the order, Primary > Secondary > Tertiary.

Answer to Problem 95E

On the basis of the number of alkyl groups, three types of amines are classified as,

1. Primary amines: Amines in which the nitrogen atom is attached to one alkyl group and two hydrogen atoms are called primary amine.

2. Secondary amines: Amines in which the nitrogen atom is attached to two alkyl groups and one hydrogen atom are called secondary amine.

3. Tertiary amines: Amines in which the nitrogen atom is attached to three alkyl groups and zero hydrogen atom are called tertiary amine.

Explanation of Solution

The nitrogen-containing organic compounds are known as amines. They are derivatives of ammonia. Substitution of one, two or three hydrogen atoms in the ammonia molecule by an alkyl group form an amine. Amines can be classified as primary, secondary or tertiary depending upon how many alkyl groups are attached to the nitrogen atom in amines.

Conclusion

Amines are called, the organic derivatives of ammonia. In an ammonia molecule, one nitrogen atom is bonded to three hydrogen atoms. When one, two or three hydrogen atoms are replaced by either an alkyl or an aryl group amine is formed. Replacement of one hydrogen atom by an alkyl group gives primary amine. Replacement of two hydrogen atoms gives secondary amines, whereas all the three hydrogen atoms when replaced by alkyl/aryl groups, tertiary amines are formed.

Interpretation Introduction

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Interpretation:

The difference between the chain-growth polymer and the step-growth polymer is to be determined.

Concept Introduction:

Polymerization is a process in which two or more monomer units combine to form long chains or three-dimensional networks.

Based on the modes of polymerization, polymers are classified as follows:

Addition polymers – Addition polymers are formed by repeated addition of the monomer units. The monomer units are unsaturated hydrocarbons generally. There is no elimination of molecules in the reaction.

Condensation polymers – Condensation polymers are formed by repeated condensation between two different monomer units along with the formation of elimination products like water.

Answer to Problem 95E

Chain growth polymers are those polymers that are synthesized from the addition reaction and step-growth polymers are those polymers that are synthesized from the condensation reaction.

Explanation of Solution

Chain growth polymers are the molecules that are synthesized from the addition reaction. In chain growth polymerization, one monomer adds to the growing polymer chain in a sequential manner resulting in a large chain-growth polymer. Generally, alkenes act as the monomer unit in these polymers.

The polymerization initiates when one bond between the carbon-carbon double bond breaks. This leads to the formation of new monomer units in which there is one unpaired electron on both atoms of the carbon double bond. The unpaired electron on the carbon atom of one monomer unit forms a bond with the neighboring monomer unit to form the polymer. The general three repeating units of the chain-growth polymer is,

Here, R is an alkyl group.

Step-growth polymers are the polymers that are synthesized by the stepwise reaction of monomer unit with the growing chain. Condensation reactions are employed for the synthesis of the step-growth polymerization reaction.

The condensation reaction of the dicarboxylic acid and diamine are employed for the synthesis of polyesters. In the condensation reaction, one molecule of water is released resulting in the formation of an amide bond $\left(-\text{CO}-\text{NH}\right)$. A general condensation reaction between dicarboxylic acid and diamine is as follows:

Conclusion

Chain growth polymers are those polymers that are synthesized from the addition reaction and step-growth polymers are those polymers that are synthesized from the condensation reaction.