4. Alkanes and Cycloalkanes

Given the following Newman projection of ethane looking down the $C–C$ bond, which of the following wedge and dash structures correctly represents the same conformation?

Which of the following diagrams correctly represents a Newman projection for propane when viewed along the $C_1–C_2$ bond?

Given the following Newman projection of ethane viewed down the $C_1-C_2$ bond, which bond-line structure does it represent? (Front carbon: three hydrogens; back carbon: three hydrogens; all staggered)

Which of the following correctly represents the staggered conformation of ethane in a Newman projection when viewed down the $C–C$ bond?

Which of the following best describes the most stable Newman projection for 2,3-dimethylbutane when viewed down the C$2$-C$3$ bond?

Which of the following best describes the most stable Newman projection for $2_{\text{-methylbutane}}$ when viewed down the $C_2–C_3$ bond?

Which of the following diagrams represents a Newman projection of butane?

Which of the following best describes a Newman projection in which the front and back substituents are positioned directly in line with each other when viewed along the carbon-carbon bond axis?

Given the following Newman projection looking down the $C_2–C_3$ bond of a straight-chain alkane, where the front carbon ($C_2$) has a methyl group, an ethyl group, and a hydrogen, and the back carbon ($C_3$) has a methyl group, a hydrogen, and an ethyl group, what is the correct IUPAC name of the compound?

Which of the following best describes the most stable Newman projection for 2,3-dimethylpentane when viewed down the C$2_{-}$C$3_{}$ bond?

Given the staggered conformation of $C_2{H}_6$ (ethane), which of the following correctly matches the front and back substituents in a Newman projection looking down the $C–C$ bond?

Construct a graph, similar to Figure 3-11, of the torsional energy of 3-methylpentane along the C2―C3 bond.

a. Place C2 in front, represented by three bonds coming together in a Y shape, and C3 in back, represented by a circle with three bonds pointing out from it.

b. Define the dihedral angle as the angle between the methyl group on the front carbon and the ethyl group on the back carbon.

Which of the following conformers of isobutyl chloride is the most stable?

Construct a graph, similar to Figure 3-11, of the torsional energy of 3-methylpentane along the C2―C3 bond.

c. Begin your graph at the 0° dihedral angle and begin to turn the front carbon.