Chapter 14, Problem 33PP

(a)

Interpretation Introduction

Interpretation:

The specific bonds in the given molecules and the wavenumber according to their absorption in given range have to be identified.

Concept introduction:

IR spectral studies: It is a spectroscopic technique which is used to determine the functional groups present in the given compound sample by absorbing characteristic frequency in particular range with respect to the group present in the given sample.

Explanation of Solution

The structure shows that the molecule contains one carbonyl group and one carbon-carbon double bond. Analyzing the structure shows that the carbonyl group and the double bonds are conjugated hence, the carbonyl group shows signal near to 1680${\text{cm}}^{\text{-1}}$ and double bond produce signal near 1600${\text{cm}}^{\text{-1}}$.

(b)

Interpretation Introduction

Interpretation:

The specific bonds in the given molecules and the wavenumber according to their absorption in given range have to be identified.

Concept introduction:

IR spectral studies: It is a spectroscopic technique which is used to determine the functional groups present in the given compound sample by absorbing characteristic frequency in particular range with respect to the group present in the given sample.

Explanation of Solution

The structure shows that the molecule contains one carbonyl group and one carbon-carbon double bond. Analyzing the structure shows that the carbonyl group and the double bond are not conjugated they are isolated hence the carbonyl group produce signal near 1720${\text{cm}}^{\text{-1}}$ and double bonds exhibit signal near 1650${\text{cm}}^{\text{-1}}$.

(c)

Interpretation Introduction

Interpretation:

The specific bonds in the given molecules and the wavenumber according to their absorption in given range have to be identified.

Concept introduction:

IR spectral studies: It is a spectroscopic technique which is used to determine the functional groups present in the given compound sample by absorbing characteristic frequency in particular range with respect to the group present in the given sample.

Explanation of Solution

The structure shows that the molecule contains one ester group. Therefore, the carbonyl group presents in the ester exhibit a signal near to 1740${\text{cm}}^{\text{-1}}$.

(d)

Interpretation Introduction

Interpretation:

The specific bonds in the given molecules and the wavenumber according to their absorption in given range have to be identified.

Concept introduction:

IR spectral studies: It is a spectroscopic technique which is used to determine the functional groups present in the given compound sample by absorbing characteristic frequency in particular range with respect to the group present in the given sample.

Explanation of Solution

The structure shows that the molecule contains one ester group and one carbon-carbon double bond where both are conjugated hence carbonyl group of ester produce signal near 1710${\text{cm}}^{\text{-1}}$ and double bond produce signal near 1600${\text{cm}}^{\text{-1}}$.