What is the prefix used for a five-carbon alkane?

The prefix used for a five-carbon alkane is "Pent-." In organic chemistry, prefixes are used to indicate the number of carbon atoms in the longest continuous chain of an alkane compound. Alkanes are saturated hydrocarbons that follow the general formula CnH2n+2, where "n" represents the number of carbon atoms.

For five carbon atoms, the prefix "Pent-" is derived from the Greek word for five. This is a standard naming convention, and when five carbon atoms are present in an alkane, the compound is called pentane. Recognizing these prefixes is essential for understanding how various hydrocarbons are named based on the number of carbon atoms they contain.

The other prefixes correspond to different numbers of carbons: "But-" is for four carbons, "Hex-" is for six carbons, and "Oct-" is for eight carbons, each contributing to the systematic naming in the nomenclature of organic compounds.