Chapter 12.18, Problem 3QQ

Interpretation Introduction

Interpretation:

The IUPAC name for the compound whose common name is propyl chloride has to be chosen from the given set of options.

Concept Introduction:

The derivative of alkane with halogen instead of one or more hydrogen atoms is known as halogenated alkane.  If the same is present in cycloalkane, then it is known as halogenated cycloalkane.  They are product of reaction between alkane/cycloalkane with halogens.

IUPAC nomenclature for halogenated alkanes/cycloalkanes:

Similar to the alkyl groups, the halogen is also treated as substituents present on the carbon chain.  They are called as fluoro-, chloro-, bromo-, and iodo-.

If the carbon chain contains both alkyl and halogen, they both are considered of equal ranks.  The numbering is done in a way so that the substituents get the least number, whether it is an alkyl or a halo group.

In IUPAC names, the groups that are present on the carbon chain are written in alphabetical order.

Common names:

Halogenated alkanes are also named as alkyl halides.  These are not IUPAC names.  They are common names.  In a common name, two parts are present.  First part is the name of the hydrocarbon (alkyl group).  Second part gives the halogen present in the compound.  The halogen is considered as though it is present as an ion even though no ions are present.

Halogenation:

Halogenation is a chemical reaction between a substance and halogen.  The product of halogenation reaction is that one or more halogens are incorporated into molecules of the substance.  Halogenation of hydrocarbon gives hydrocarbon derivatives as product where halogen atoms are substituted instead of hydrogen atoms.

Halogenation reaction of alkane is an example of substitution reaction.  This is a reaction where a part of reacting molecule replaces an atom or group of atoms in hydrocarbon or hydrocarbon derivative.