Regents Chemistry Exam August 2022
46. Given the formula representing a compound:
What is a chemical name for the compound?
(1) 2-chloropentene
(2) 2-chloropentane
(3) 4-chloropentene
(4) 4-chloropentane
Explanation: The structure of the molecules has carbons and hydrogens representing an organic molecules. We see all single bonds which means this is an alkane. The name must end in "ane", eliminating choices 1 and 3. Next, we find the longest carbon chain. In this case, it is five carbons. Table P on the reference table shows that the prefix for five carbons is pent, making the parent chain pentane. Finally, we number the carbons from the end closest to chlorine, from the right. Chlorine is on the second carbon from the right and the molecule should be named 2-chloropentane.
Answer: 2