Final answer:
To draw a Newman projection of 1-chlorobutane, focus on the C2-C3 bond, depict the front atom with its three substituents including chlorine as a central dot with radiating bonds, and the back atom similarly with a larger circle, aiming for a staggered conformation.
Step-by-step explanation:
To draw a Newman projection of 1-chlorobutane, envision looking straight down the bond between the second and third carbon atoms (C2-C3). In a Newman projection, the front atom (C2 in 1-chlorobutane) is represented by a dot with three bonds extending outwards, while the back atom (C3) is represented by a larger circle, with its three bonds radiating backward from the circle to indicate the spatial relationship.
Begin with the parent chain of butane, which is four carbon atoms long, represented as -C-C-C-C-. The chlorine atom will be attached to the first carbon. When looking down the C2-C3 bond for 1-chlorobutane, you'll position the chlorine atom (Cl) at the front carbon along with two hydrogen atoms (H), spread 120° apart, extending from the central dot. The back carbon will have its three hydrogen atoms depicted in a similar manner, extending from the larger circle that represents C3. Typically, the lowest-energy conformation is the staggered conformation, where the front and back atoms' bonds are maximally spaced at a dihedral angle of 60° and seemingly in between each other when viewed from the front carbon.