Chapter 20.2, Problem 5RQ

a.

Interpretation Introduction

Interpretation:The compounds C₆H₁₂ and C₆H₆ are to be named and their structures are to be drawn.

Concept Introduction:The carbon compounds are named according to IUPAC convention.

Answer to Problem 5RQ

The compounds C₆H₁₂ and C₆H₆are called cyclohexane and benzene respectively.

  

Explanation of Solution

The above structures represent C₆H₁₂ and C₆H₆in stick form and they are standard compounds whose names are fixed by the IUPAC convention.

b.

Interpretation Introduction

Interpretation:The similarity of the compounds C₆H₁₂ and C₆H₆is to be written.

Concept Introduction:The similarity of the given compounds is primarily their structure.

Answer to Problem 5RQ

The similarity of C₆H₁₂ and C₆H₆is that they are both cyclic compounds with a six carbon primary chain.

Explanation of Solution

Both cyclohexane and benzene have six carbon cyclic chain and both of them are planar so their bond angles and ring structure are also similar.

c.

Interpretation Introduction

Interpretation:Thedifferencebetween the compounds C₆H₁₂ and C₆H₆ is to be written.

Concept Introduction:Thedifference of the given compounds lies in their chemical properties.

Answer to Problem 5RQ

C₆H₁₂is a saturated cycloalkane and is an aliphatic compound so it gives non sooty flame and has non-pleasant smell. On the other hand, C₆H₆is an unsaturated compound and is aromatic. It gives a sooty flame and has a pleasant smell.

Explanation of Solution

All the differences between cyclohexane and benzene is due to the resonating pi electron system of benzene which gives the compound its aromatic properties and makes it different from cyclohexane.

d.

Interpretation Introduction

Interpretation: Whether C₆H₁₂ will react by addition or substitution is to be written.

Concept Introduction: The preference for addition or substitution reactions depends on the presence of pi bonds.

Answer to Problem 5RQ

C₆H₁₂prefers to undergo substitution reaction and not addition reaction.

Explanation of Solution

C₆H₁₂ is a saturated cycloalkane and all of its carbon atoms are sp³ hybrid with absence of any pi-bonding, therefore it cannot undergo addition reaction and prefers substitution reaction.