Quiz - Cycloalkanes - 1 | Cycloalkanes

Organic Chemistry 1 - Quiz - Cycloalkanes - 1

1

What is the general formula of regular cycloalkanes?

Alkanes: CnH2n+2;   Cycloalkanes: CnH2n

2

What term describes the spatial arrangement of atoms in cycloalkanes that results from the rotation about single bonds?

Conformers, also known as conformational isomers, are the different spatial arrangements of atoms that result from the rotation about single bonds. Unlike resonance structures or tautomers, conformers exist due to the inherent flexibility of single bonds allowing for rotation without breaking the bond.

3

What is the most stable cycloalkane?

By adopting a chair conformation, cyclohexane is free of bond-angle and eclipsing strain, which is not the case for cyclobutane, cyclopentane or cycloheptane

4

In substituting cyclohexane with tert-butyl groups, which position predisposes the molecule to the lowest energy state?

Substituting cyclohexane with bulky tert-butyl groups in equatorial positions tends to lower the energy state of the molecule due to reduced steric hindrance.

5

Which of the following is an acceptable IUPAC name?

When 2 numbering sequences are possible for a polysubstituted system, the substituents are listed in alphabetical order

6

What is the most stable conformer of 1-bromo-2-methylcyclohexane?

Disubstituted cyclohexane: the more stable conformer is the conformer with its 2 substituents in equatorial position in order to avoid 1,3-diaxial interactions

7

What is the consequence of 1,3-diaxial interactions in mono-substituted cyclohexanes?

1,3-diaxial interactions result in steric hindrance between axial substituents and hydrogens on the same side of the ring, creating additional strain and decreasing the stability of the molecule's chair conformation.

8

What is the most stable stereoisomer of 1,4-dimethylcyclohexane?

The more stable conformer is the conformer with the maximum substituents in equatorial position
 

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9

What does a Newman projection represent in organic chemistry?

A Newman projection provides a top-down view of a molecule along a specific bond, showing the relative positions of atoms and groups.

10

What does a fully eclipsed conformation represent in a Newman projection?

A fully eclipsed conformation in a Newman projection represents a high-energy state due to increased steric hindrance between substituents.