Chapter 17, Problem 17.92P

Answer the following questions about B, depicted in the ball-and-stick model
a. What is the IUPAC name for B?
b. Draw an isomer of B that has the same functional group.
c. Draw an isomer of B that has a different functional group.
d. What products are formed when B is treated with NaOH?
e. Predict the solubility properties of B in ${\text{H}}_{\text{2}}\text{O}$ ; in an organic solvent.
f. What product is formed when B is treated with ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}\text{OH}$ and ${\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}$ ?
g. What product is formed when B is heated with ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{NH}}_{\text{2}}$ ?

Interpretation Introduction

(a)

Interpretation:

The IUPAC name for the given ball and stick model should be determined.

  

Concept Introduction:

Functional groups are the groups of atoms or atoms which are bonded with parent carbon chain in the organic molecule and are responsible for the physical and chemical properties of the compound. In organic chemistry, there are different functional groups such as carboxylic acid, alcohol, ester, or amide.

Answer to Problem 17.92P

8,8-dimethylnonanoic acid.

Explanation of Solution

In the given ball and stick model of the compounds;

Black ball = C atom

White ball = H atom

Red ball = O atom

Blue ball = N atom

To assign the acceptable name to the compound, the IUPAC rules must be followed:

• Check the longest C chain and assign root word for that.
• Add prefix for the branch or side chain with its position.
• Add di, tri, tetra prefix for more than one prefix.
• The primary suffix indicates the single, double and triple bond in the molecule.
• Secondary suffix indicates the presence of functional group in the molecule.

  

Interpretation Introduction

(b)

Interpretation:

The constitutional isomer of 8,8-dimethylnonanoic acid which has same functional group should be determined.

Concept Introduction:

Functional groups are the groups of atoms or atoms which are bonded with parent carbon chain in the organic molecule and are responsible for the physical and chemical properties of the compound. In organic chemistry, there are different functional groups such as carboxylic acid, alcohol, ester, or amide.

Answer to Problem 17.92P

  

Explanation of Solution

Constitutional isomers are the isomers with same molecular formula but different arrangement of bonded atoms in the molecule. The constitutional isomer of 5-methylhexanoic acid which has same functional group must have same molecular formula but different structural arrangement of bonded atoms.

  

Interpretation Introduction

(c)

Interpretation:

The constitutional isomer of 8, 8-dimethylnonanoic acid which has different functional group should be determined.

Concept Introduction:

Functional groups are the groups of atoms or atoms which are bonded with parent carbon chain in the organic molecule and are responsible for the physical and chemical properties of the compound. In organic chemistry, there are different functional groups such as carboxylic acid, alcohol, ester, or amide.

Answer to Problem 17.92P

  

Explanation of Solution

Constitutional isomers are the isomers with same molecular formula but different arrangement of bonded atoms in the molecule. The constitutional isomer of 8, 8-dimethylnonanoic acid which has different functional group must have same molecular formula but different functional group like ester as ester and carboxylic acid are functional isomers of each other.

  

Interpretation Introduction

(d)

Interpretation:

The products formed when the given carboxylic 8, 8-dimethylnonanoic acid react with NaOH should be determined.

Concept Introduction:

Functional groups are the groups of atoms or atoms which are bonded with parent carbon chain in the organic molecule and are responsible for the physical and chemical properties of the compound. In organic chemistry, there are different functional groups such as carboxylic acid, alcohol, ester, or amide.

Amines are the organic compounds with general chemical formula of R-NH₂ or R-NH-R whereas carboxylic acids are the organic molecules with R-COOH as general chemical formula.

Answer to Problem 17.92P

  

Explanation of Solution

The reaction of carboxylic acid with base like NaOH is an acid-base reaction that leads to the formation of salt and water.

It is also called as neutralization reaction. In these reactions the carboxylic acid gives H⁺ ions that combines with OH- ion from base and forms water. The carboxylate ion converts to sodium salt due to presence of Na⁺ ions in the solution.

  

Interpretation Introduction

(e)

Interpretation:

The solubility of 8, 8-dimethylnonanoic acid in water and organic solvent should be predicted.

Concept Introduction:

Functional groups are the groups of atoms or atoms which are bonded with parent carbon chain in the organic molecule and are responsible for the physical and chemical properties of the compound. In organic chemistry, there are different functional groups such as carboxylic acid, alcohol, ester, or amide.

Answer to Problem 17.92P

8, 8-dimethylnonanoic acid is less soluble in water but soluble in organic solvents.

Explanation of Solution

Organic compounds like hydrocarbons are composed of C and H atoms. They mainly have C-C and C-H bonds in their structure.

Since both C-C and C-H bonds are non-polar in nature therefore hydrocarbons like alkanes are non-polar compounds therefore it is soluble in non-polar solvents like organic solvents.

The 8, 8-dimethylnonanoic acid is a polar compound due to −COOH group and must form hydrogen bonds with water molecule but due to bulky alkyl group in the molecule it is very difficult for the molecule to form hydrogen bonds with water molecule. Therefore 8, 8-dimethylnonanoic acid is insoluble in water and soluble in organic solvents.

Interpretation Introduction

(f)

Interpretation:

The reaction of 8, 8-dimethylnonanoic acid with ethanol in the presence of H₂SO₄ should be determined.

Concept Introduction:

Functional groups are the groups of atoms or atoms which are bonded with parent carbon chain in the organic molecule and are responsible for the physical and chemical properties of the compound. In organic chemistry, there are different functional groups such as carboxylic acid, alcohol, ester, or amide.

Alcohols are the organic compounds with general chemical formula of R-OH whereas carboxylic acids are the organic molecules with R-COOH as general chemical formula.

Answer to Problem 17.92P

  

Explanation of Solution

The German chemist Emil Fischer purposed the reaction of carboxylic acid with alcohol in acidic medium to form ester and water. The reaction occurs in the presence of concentrated sulfuric acid. In this reaction the alcohol carbon atom react with carbonyl carbon atom of carboxylic acid to form ester.

The reaction of 8, 8-dimethylnonanoic acid with ethanol leads to formation of water and ester that must have −COO- group in the molecule.

  

Interpretation Introduction

(g)

Interpretation:

The reaction of 8, 8-dimethylnonanoic acid with ethylamine should be determined.

Concept Introduction:

Functional groups are the groups of atoms or atoms which are bonded with parent carbon chain in the organic molecule and are responsible for the physical and chemical properties of the compound. In organic chemistry, there are different functional groups such as carboxylic acid, alcohol, ester, or amide.

Alcohols are the organic compounds with general chemical formula of R-OH whereas carboxylic acids are the organic molecules with R-COOH as general chemical formula.

Answer to Problem 17.92P

  

Explanation of Solution

The reaction of carboxylic acid with ammonia or amines forms amide molecules. It involves the formation of water molecule. In this reaction the amine nitrogen atom react with carbonyl carbon atom of carboxylic acid to form amide.

The reaction of 8, 8-dimethylnonanoic acid with ethylamine leads to formation of water and amide that must have −CONH- group in the molecule.