Reactions of organic compounds Flashcards
What is an addition reaction?
Involves the breaking of the C=C double bond, allowing another molecule to combine to form the larger one.
Give a description of an addition reaction?
- involves an unsaturated compound
- one product is formed
Under what conditions does an addition reaction occur?
For alkenes:
- UV light
What is hydrogenation?
Under what conditions does this reaction occur?
The addition of hydrogen to an unsaturated compound Forms saturated compound (alkane) Requires: - metal catalyst: Ni - 600˚c
What is a hydration reaction?
Under what conditions does this reaction occur?
Addition of water to an unsaturated Requires: - HPO3 - catalyst - 300˚c
What is halogenation? (4)
- Addition of a halogen to an unsaturated compound
- Forms a haloalkane
- Allows product to undergo more reactions due to the presence of more electronegative atom, thus compound is more unstable
- Allows for alcohols and amines to be produced
How can an amine be produced?
Chloroalkane + concentrated ammonia
What is addition polymerisation?
Small unsaturated monomers are joined together to form a polymer.
What is a substitution reaction?
Replacement of an atom or group of atoms by another.
Give a description of a substitution reaction.
- usually involves saturated molecule
- two new products are formed
- if reactant is concentrated, further reactions could occur, resulting in all hydrogens replaced with Cl
Under what conditions does a substitution reaction occur?
Requires:
- UV light
- heat
- catalyst (since reaction is slow)
How would you separate molecules which have undergone substitution from those which have not undergone substitution?
The different substituted products have different boiling points so they may be separated from one another by fractional distillation.
How can an alcohol be produced from a haloalkane?
- Because of the large electronegativity difference between Cl and C, there will be a polar bond
- As a consequence of the highly polarised bond, the partial positive charge on the C atom can be attacked by a negatively charged species such as a hydroxide ion
- RCl ——-> ROH + HCl
OH-
What is the oxidation reaction of alcohols?
Involves a change in oxidation numbers as the alcohol is oxidised to form
Write the equation for the reaction between a chloroalkane and a water molecule.
Chloroethane + H2O ————> Ethanol + HCl
Catalyst
Requires a catalyst to speed up the reaction.