Halogenoalkanes Flashcards
What is a halogenoalkane?
What is a halogenoalkane?
An alkane with at least one halogen atom in place of a hydrogen atom
Explain why halogen – Carbon bonds are polar
Explain why halogen – Carbon bonds are polar
Halogen atoms are generally more electronegative than carbon atoms and so they withdraw electron density from carbon atoms this leaves the carbon atoms with a partial positive charge and the halogen atoms with a partial negative charge - resulting in a polar bond
what is a nucleophile
what is a nucleophile
An electron pair donor
Give two examples of nucleophiles that will react with halogenoalkanes
Give two examples of nucleophiles that will react with halogenoalkanes
NH3
CN-
What does a pair of dots represent on a nucleophile?
What does a pair of dots represent on a nucleophile?
A lone pair of electrons
Draw the mechanism for the reaction of 1-chlorobutane with warm ethanolic potassium cyanide
the molecule is shown below
Ch3Ch2Ch2Ch2Cl
Draw the mechanism for the reaction of 1-chlorobutane with warm ethanolic potassium cyanide
the molecule is shown below
Ch3Ch2Ch2Ch2Cl
Which of the following reactions would be quickest explain your answer
A: CH3CH2CL + H20 —> CH3CH2OH + HCl
B: CH3CH2Br + H2O —> CH3CH2OH + HBR
C: CH3CH2I + H2O —> CH3CH2OH + HI
Which of the following reactions would be quickest explain your answer
A: CH3CH2CL + H20 —> CH3CH2OH + HCl
B: CH3CH2Br + H2O —> CH3CH2OH + HBR
C: CH3CH2I + H2O —> CH3CH2OH + HI
C, Because the C-I has the lowest bond enthalpy of all the carbon – halogen bonds.
this means that the C-I bond is the easiest to break and therefore this reaction will happen the quickest
Draw the mechanism for the reaction of Iodopropane with ammonia the reaction is done in a sealed tube of warm ethanol.
the reactants are shown below.
CH3CH2CH2I
:NH3
Draw the mechanism for the reaction of Iodopropane with ammonia the reaction is done in a sealed tube of warm ethanol.
the reactants are shown below.
CH3CH2CH2I
:NH3
Draw the mechanism for the hydrolysis of chloroethane by warm aqueous sodium hydroxide
Draw the mechanism for the hydrolysis of chloroethane by warm aqueous sodium hydroxide
What happens in the nucleophilic substitution reaction
What happens in the nucleophilic substitution reaction
One functional group is substituted for another
What chemical would you react with bromoethane to get ethanol?
What chemical would you react with bromoethane to get ethanol?
Aqueous sodium hydroxide or potassium hydroxide
Name the nucleophile that is present when bromoethane reacts with ethanolic potassium cyanide under reflux
Name the nucleophile that is present when bromoethane reacts with ethanolic potassium cyanide under reflux
Cyanide ion
Under what reaction conditions do you react bromoethane with ammonia to form ethylamine
Under what reaction conditions do you react bromoethane with ammonia to form ethylamine
Warm in ethanol in a sealed tube
Explain why Fluoroalkanes are substituted more slowly than other Halogenoalkanes
Explain why Fluoroalkanes are substituted more slowly than other Halogenoalkanes
The C-F bond is the strongest – it has the highest bond enthalpy so fluoroalkanes are substituted more slowly than other halogenoalkanes
