Module 4 Chapter 15 Flashcards
What can haloalkanes be classified as
primary, secondary and tertiary haloalkanes
What are primary haloalkanes
The carbon attached to group 7 atom has one alkyl group attached to
What are secondary haloalkanes
The carbon attached to group 7 atom has two alkyl group attached
What are tertiary haloalkanes
The carbon attached to the group 7 atom has three alkyl groups attached to
What is a property of the carbon halogen bond and why
Carbon - halogen bond
halogens are very electronegative
So the electron pair moves closer to the halogen, creating different charged regions
Making it polar
What is the halogen in the bond and the carbon in the bond
The halogen has a partial negative charge and the carbon is partially positively charged.
What can the carbon that is partially positively charged do
It can attract a species containing a lone pair of electrons
What are nucleophles
A species that can donate a lone pair of electrons, a group of atoms, that is attracted to an an electron deficient carbon atom and a new covalent bond forms.
What are some common nucleophiles
Hydroxide ions : OH-
water molecules - H2O
Ammonia molecules - NH3
What happens in the reaction with a nucleophile
The nucleophile replaces the halogen in a substitution reaction. And a new compound is formed with a different functional group.
What is the reaction when the nucleophile replaces a hydrogen atom called
Nucleophilic substitution
What do primary haloalkanes undergo lots of
They undergo lots of different nucleophilic substitution reactions to produce lots of different compounds.
What is a substitution reaction
A reaction in which one atom or group of atoms are replaced by another atom or groups of atoms.
What occurs in the hydrolysis of haloalkanes
The reaction involves water or an aqueous solution of a hydroxide that causes the breaking of a bond in a molecule.
You get two products.
Halogens are replaced by the -OH group in a nucleophilic substitution reaction
What are the steps for the hydrolysis of haloalkanes
The nucleophile approaches the carbon attached to the halogen on the opposite side of the molecule from the halogen.
Draw the mechanism for the nucleophilic substitution of the hydroxide ion with the haloalkane
DRAW IT
How are haloalkanes converted to alcohols (conditions and reactants)
Using sodium hydroxide
Where they are heated under reflux to get a good yield.
What does the rate of hydrolysis depend on
It depends on the strength of carbon-halogen bonds in haloalkanes.
What is the order of strength of the carbon-halogen bonds
C-F»C-CL»C-I
As a result of the bond strengths what are the most reactive haloalkanes and the least reactive haloalkanes
Iodoalkanes react the fastest
Fluoroalkanes are unreactive as a large amount of energy is required to break the C-F bond.
How can the rate of reaction be followed
With a reaction in the presence of aqueous silver nitrate, where the halide ions produced react with silver ions to form a silver precipitate.
What is the nucleophile present in the reaction with aqueous silver nitrate
The water present.
Because haloalkanes are insoluble in water, what is the reaction done with
An ethanol solvent allowing the water and haloalkanes to mix and produce a single solution
What are the observations when the different haloalkanes undergo hydrolysis reactions in the presence of silver nitrate
1-chlorobutane A white precipitate forms very slowly
1-bromobutane A cream precipitate forms slowed than with 1-iodobutane but faster than with 1-chlorobutane
1-iodobutane A yellow precipitate forms rapidly
