NCERT Book Class 12 Chemistry Chapter 6 Haloalkanes and Haloarenes

Unit

Objectives
6
Haloalkanes and
After studying this Unit, you will be
able to
· name haloalkanes and haloarenes
Haloar enes
Haloarenes
according to the IUPAC system of
nomenclature from their given
structures; Halogenated compounds persist in the environment due to their
· describe the reactions involved in resistance to breakdown by soil bacteria.
the preparation of haloalkanes and
haloarenes and understand
various reactions that they The replacement of hydrogen atom(s) in an aliphatic
undergo; or aromatic hydrocarbon by halogen atom(s) results
· correlate the structures of in the formation of alkyl halide (haloalkane) and aryl
haloalkanes and haloarenes with halide (haloarene), respectively. Haloalkanes contain
various types of reactions; halogen atom(s) attached to the sp3 hybridised carbon
· use stereochemistry as a tool for atom of an alkyl group whereas haloarenes contain
understanding the reaction
halogen atom(s) attached to sp2 hybridised carbon
mechanism;
atom(s) of an aryl group. Many halogen containing
· appreciate the applications of
organo-metallic compounds;
organic compounds occur in nature and some of
these are clinically useful. These classes of compounds
· highlight the environmental effects
of polyhalogen compounds. find wide applications in industry as well as in day-
to-day life. They are used as solvents for relatively
non-polar compounds and as starting materials for
the synthesis of wide range of organic compounds.
Chlorine containing antibiotic, chloramphenicol,
produced by microorganisms is very effective for the
treatment of typhoid fever. Our body produces iodine
containing hormone, thyroxine, the deficiency of which
causes a disease called goiter. Synthetic halogen
compounds, viz. chloroquine is used for the treatment
of malaria; halothane is used as an anaesthetic
during surgery. Certain fully fluorinated compounds
are being considered as potential blood substitutes
in surgery.
In this Unit, you will study the important methods
of preparation, physical and chemical properties and
uses of organohalogen compounds.