Compounds in which hydrogen atoms in a hydrocarbon molecule are replaced by halogen atoms are called haloalkane, or simply haloalkanes.
The general formula for haloalkanes is (Ar)R-X, where X is a halogen atom, which can be considered the functional group of the haloalkane, including fluorine, chlorine, bromine, and iodine.
Nomenclature: Based on the different substituted halogens, they are called fluorinated hydrocarbons, chlorinated hydrocarbons, bromine hydrocarbons, and iodinated hydrocarbons; they can also be classified according to the number of halogen atoms in the molecule as monohalogenated hydrocarbons, dihalogenated hydrocarbons, and polyhalogenated hydrocarbons; they can also be classified according to the different hydrocarbon groups as saturated haloalkanes, unsaturated haloalkanes, and aromatic haloalkanes, etc.
Furthermore, they can be classified according to the different carbon atoms directly bonded to the halogen atom as primary haloalkanes (RCH2X), secondary haloalkanes (R2CHX), and tertiary haloalkanes (R3CX).
Test Method
① Mix the haloalkanes with excess NaOH solution (heat), shake thoroughly, and let stand;
② Then add excess dilute HNO3 to the mixture to neutralize the excess NaOH;
③ Finally, add AgNO3 solution to the mixture. If a white precipitate forms, it proves that it is a chlorinated hydrocarbon; if a light yellow precipitate forms, it proves that it is a bromine hydrocarbon; if a yellow precipitate forms, it proves that it is an iodinated hydrocarbon.