3.3. Haloalkanes Flashcards
State the reagents and conditions needed to make a haloalkane from an alkane
Reagent: Cl2, Br2
Condition: UV light
Why is UV light the essential condition required to make a haloalkane from an alkane
Breaks the halogen-halogen bond to form a radical and start the reaction
State the mechanism needed to make a haloalkane from an alkane
Radical Substitution
When making a haloalkane from an alkane how would you reduce the amount of further subsitution occuring
add excess alkane
State the definition of a free radical
A species with an unpaired electron
State the reagents and conditions needed to make a haloalkane from an alkene
Reagent: HCl, HBr
Condition: Room temperature and shake
State the mechanism needed to make a haloalkane from an alkene
Electrophilic Addition
State the reagents and conditions needed to make an alkene from a haloalkane
Reagent: NaOH/KOH
Condition: Ethanolic (reflux)
State the mechanism needed to make an alkene from a haloalkane
Elimination
State the reagents and conditions needed to make an alcohol from a alkene in a single step
Reagent: Steam
Condition: Concentrated phosphoric acid
State the mechanism needed to make an alkyl hydrogen sulfate from a alkene
Electrophilic Addition
State the reagents and conditions needed to make a nitrile from a haloalkane
Reagent: KCN
Condition: Aqueous and ethanolic
State the mechanism needed to make a nitrile from a haloalkane
Nucleophilic Substitution
State the reagents and conditions needed to make an alcohol from a haloalkane
Reagent: NaOH/KOH
Condition: Aqueous (heat under reflux)
State the mechanism needed to make an alcohol from a haloalkane
Nucleophilic Substitution
State the reagents and conditions needed to make a primary amine from a haloalkane in one step
Reagent: NH3
Condition: Excess
(ethanol, heat and pressure)
State the mechanism needed to make a primary amine from a haloalkane in one step
Nucleophilic Substitution
State the type of reaction needed to make a primary amine from a nitrile
Reduction
State the reagents and conditions needed to make a primary amine from a haloalkane in two steps
**First **
Reagent: KCN
Condition: Aqueous and Ethanolic
Second
Reagent: Hydrogen
Condition: Nickel Catalyst
Explain why a haloalkane such as chloromethane is attacked by a nucleophile in a nucleophilic substitution reaction
Chlorine is more electronegative than carbon. Carbon is partially positive. Lone pair on nucleophile is attracted to the carbon
Define a nucleophile
electron pair donor
Define an electrophile
electron pair acceptor
Why does 1-iodobutane have a faster rate of hydrolysis than 1-chlorobutane?
C-I bond is weaker than C-Cl bond (less energy is required to break the bond)
Write an equation for the reaction of ethane with chlorine to form chloroethane and a by-product
Write an equation for the reaction of propane with bromine to form 2-bromopropane and a by-product
Write the propagation steps involved in the formation of chloroethane from chlorine and ethane
Write the propagation steps involved in the formation of 2-bomoprpane from bromine and propane
Write the propagation steps involved in the formation of 1-chlorobutane from chlorine and butane
Desribe what happens in the termination stage of free-radical substitution
two radicals combine
Outline the mechanism for the formation of propan-2-ol from 2-bromo propane
Outline the mechanism for the formation of but-1-ene from 2-chlorobutane
Define Structural Isomers
Molecules with the same molecular formula but different structural formulae
Define steroisomerism
Molecules with the same molecular and structural formulae but different arrangement of atoms in space
