Chapter 5, Problem 47P

(a)

Interpretation Introduction

Interpretation:

More stable alkene should be identified from the given alkenes.

Concept introduction:

The amount of heat released in a hydrogenation reaction is known as heat of hydrogenation$\left(\Delta H^0\right)$.

The most stable alkene has the smallest heat of hydrogenation.

The stability of an alkene increases as the number of alkyl substituents bonded to its $s{p}^2$ carbon increases.

The stability of an alkene increases as the number of hydrogen bonded to its $s{p}^2$ carbon decreases.

(b)

Interpretation Introduction

Interpretation:

Compound with largest heat of hydrogenation has to be identified from the given alkenes.

Concept introduction:

The amount of heat released in a hydrogenation reaction is known as heat of hydrogenation$\left(\Delta H^0\right)$.

The most stable alkene has the smallest heat of hydrogenation.

The stability of an alkene increases as the number of alkyl substituents bonded to its $s{p}^2$ carbon increases.

The stability of an alkene increases as the number of hydrogen bonded to its $s{p}^2$ carbon decreases.

(c)

Interpretation Introduction

Interpretation:

Compound with smallest heat of hydrogenation has to be identified from the given alkenes.

Concept introduction:

The amount of heat released in a hydrogenation reaction is known as heat of hydrogenation$\left(\Delta H^0\right)$.

The most stable alkene has the smallest heat of hydrogenation.

The stability of an alkene increases as the number of alkyl substituents bonded to its $s{p}^2$ carbon increases.

The stability of an alkene increases as the number of hydrogen bonded to its $s{p}^2$ carbon decreases.