Chapter 23, Problem 93A

a)

Interpretation Introduction

Interpretation: To write the condensed formula for the compounds given.

Concept Introduction: Condensation formula represents the atoms present in the molecule in the form of a general formula, showing no bonds. The condensed structural formula also represents the exact number of atoms present in the molecule.

Answer to Problem 93A

  ${\text{(CH(CH}}_{\text{3}}\text{)CH}\left({\text{CH}}_{\text{3}}{\text{)CH}}_{\text{2}}{\text{CH}}_{\text{2}}\right)\text{-}$

Explanation of Solution

Generally, there will be four carbons in cyclobutene each attached to two hydrogens. In the case of 1,2-dimethylcyclobutane one of the hydrogens at the first and the second carbon got replaced with the methyl group. Therefore, the molecular formula will be ${\text{C}}_{\text{6}}{\text{H}}_{\text{12}}$ . Four carbons of Cyclobutane and the other two carbons of the methyl group. 6 hydrogens correspond to the methyl group and the other 6 hydrogens are from Cyclobutane.

b)

Interpretation Introduction

Interpretation: To write the condensed formula for the compounds given.

Concept Introduction: Condensation formula represents the atoms present in the molecule in the form of a general formula, showing no bonds. The condensed structural formula also represents the exact number of atoms present in the molecule.

Answer to Problem 93A

  ${\text{CH}}_{\text{3}}{\text{C(CH}}_{\text{3}}{\text{)CHCH}}_{\text{2}}{\text{CH}}_{\text{3}}$

Explanation of Solution

There is only a single carbon that is attached to the two methyl groups which show that there is a double bond present to satisfy the valency of carbon. There is also only one hydrogen attached to the carbon that is present next to the carbon that is attached to the methyl group. This also gives information about the double bond.

c)

Interpretation Introduction

Interpretation: To write the condensed formula for the compounds given.

Concept Introduction: Condensation formula represents the atoms present in the molecule in the form of a general formula, showing no bonds. The condensed structural formula also represents the exact number of atoms present in the molecule.

Answer to Problem 93A

  ${\text{CH}}_{\text{3}}{\text{CHCHCH}}_{\text{3}}$

Explanation of Solution

This condensed formula shows that there is a double bond between the two carbons in this molecule. The presence of the double bond will make it an alkene. Since there are four carbons it is called but and since there is a double bond it is called butene. The double is present between the second and third carbon hence, it is 2-butene. The presence of a double bond is noticed as there is only one hydrogen attached to both the second and the third carbon.

d)

Interpretation Introduction

Interpretation: To write the condensed formula for the compounds given.

Concept Introduction: Condensation formula represents the atoms present in the molecule in the form of a general formula, showing no bonds. The condensed structural formula also represents the exact number of atoms present in the molecule.

Answer to Problem 93A

  ${\text{CH}}_{\text{3}}{\text{CCCH}}_{\text{2}}{\text{CH}}_{\text{3}}$

Explanation of Solution

From the condensed formula, it is clear that both the carbons that are the second and the third carbon are not attached to any hydrogens. This clearly shows that there is a presence of a triple bond between the second and the third carbon and there are five carbons in total. Hence, this shows that the condensed formula is of 2-Pentyne which is an alkyne.

e)

Interpretation Introduction

Interpretation: To write the condensed formula for the compounds given.

Concept Introduction: Condensation formula represents the atoms present in the molecule in the form of a general formula, showing no bonds. The condensed structural formula also represents the exact number of atoms present in the molecule.

Answer to Problem 93A

  ${\text{CH}}_{\text{2}}{\text{CH(CH}}_{\text{3}}{\text{)CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_2{\text{CH}}_{\text{3}}$

Explanation of Solution

The first carbon is attached to only two hydrogens which shows that there is a double bond between the first and the second carbon. There is a methyl group that is attached to the second carbon this shows that the position of the methyl group is at the second carbon. Therefore, the condensed formula depicts the 2-methylhexene.