Haloalkanes (nucleophilic substitution and Elimination) Flashcards
What is a nucleophile?
an electron pair donor (usually a lone pair or the delta - end of a polar molecule)
What is an electrophile?
an electron pair acceptor
What does electronegative mean?
The ability of an atom to attract a shared pair of electrons in a covalent bond. Electronegative molecules have a slight negative charge and form polar bonds.
What is a substitution reaction?
Where a group takes the place of a halogen in a haloalkane molecule
What are the conditions for nucleophilic substitution of OH- to a haloakane?
Heat under reflux with an aqueous solution of sodium or potassium hydroxide.
What is reflux?
Heating with a condenser placed vertically in the flask to prevent loss of volatile substances from the mixture.
Why can OH- act as a nucleophile?
It has a pair of electrons it can donate.
What are the conditions for nucleophilic substitution of a cyanide ion into a haloalkane?
Heat under reflux with a solution of sodium or potassium cyanide in ethanol. (if you use cyanide in water OH- substitutes instead)
What does a cyanide ion look like?
-CN
Why can haloalkane molecules undergo nucleophilic substitution?
The carbon- halogen bond is polar because halogens are more electronegative than carbon (d+C-Xd-)
What does hydrolysis mean?
Hydrolysis is a reaction involving the breaking of a bond in a molecule using water.
What are the conditions for nucleophilic substitution of ammonia into haloalkanes?
Heat with a concentrated solution of ammonia in ethanol.
What is an elimination reaction?
A reaction in which a pair of atoms or groups of atoms are removed from a molecule.
What are the conditions for the elimination reaction of a haloalkane to make an alkene?
Heat under reflux with a concentrated solution of sodium or potassium hydroxide in ethanol
