Unit 3-Haloalkanes Flashcards
What is a haloalkane (halogenoalkane or alkyl halide)?
Haloalkanes are substituted alkanes in which one or more of the hydrogen atoms are replaced with a halogen atom
What is a monohaloalkane?
Substituted alkane containing only one halogen atom
Explain the difference between a primary, secondary and tertiary monohaloalkane.
Classified according to the number of alkyl
groups attached to the carbon atom containing the halogen atom
What types of reactions can monohaloalkanes undergo?
Elimination reactions to form alkenes and nucleophilic substitution reactions to form alcohols, ethers or nitriles.
How can monohaloalkanes be converted into alkenes?
Undergo elimination reaction using a strong base, such as
potassium or sodium hydroxide in ethanol
How would a monohaloalkane be converted into an alcohol?
Take part in nucleophilic substitution reaction with aqueous alkalis
How would a monohaloalkane be converted into an ether?
Take part in nucleophilic substitution reaction with alcoholic alkoxides
How would a monohaloalkane be converted into an nitrile?
Take part in nucleophilic substitution reaction with ethanolic cyanide
How would a monohaloalkane be converted into an alkene?
Take part in elimination reactions using a strong base, such as
potassium or sodium hydroxide in ethanol.
(ethanol –> elimination)
What are the two types of nucleophilic substitution?
SN1 and SN2
What is the difference between SN1 and SN2 reactions?
SN1 is a nucleophilic substitution, 1st order
SN2 is a nucleophilic substitution, 2nd order
What type of intermediate is formed in an SN1 reaction?
trigonal planar carbocation
What type of intermediate is formed in an SN2 reaction?
a single five-centred, trigonal bipyramidal transition state
Which type of haloalkane is most likely to react by an SN2 reaction?
Primary haloalkanes most likely and tertiary haloalkanes are least likely to proceed by a SN2 reaction mechanism
Which type of haloalkane is most likely to react by an SN1 reaction?
Tertiary haloalkanes are the most likely and primary haloalkanes the least likely to proceed by a SN1 reaction mechanism.
