Creado por Bee Brittain
hace más de 8 años
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Pregunta | Respuesta |
Explain why a carbon-halogen bond is polar. | A Carbon-Halogen bond is polar because halogens are more electronegative than carbon. This means the pair of electrons move close to the halogen creating a slightly negative halogen atom, and a slightly positive carbon atom. |
Define 'Nucleophile' | A nucleophile is an electron pair donor |
Give three examples of nucleophiles | Hydroxide = :OH- Water = H2O: Ammonia Molecules = :NH3 |
When a haloalkane reacts with a nucleophile, the nucleophile replaces the hydrogen in what type of reaction? What is the name of the specific reaction for nucleophiles? | Type of Reaction: Substitution Reaction Name of Reaction: Nucleophilic Substitution |
In the mechanism for nucleophillic substitution, does the nucleophile approach the carbon atom at the same side, or opposite side of the halogen atom? Explain why | It approaches from the opposite side, this is because the Carbon-Halogen bond is polar so the halogen is slightly negative, and the nucleophile is also negative, so if they were on the same side the charges would repel |
After the nucleophile has approached the carbon, what happens next in the mechanism for Nucleophillic Substitution? | The lone electron pair on the nucleophile is attracted to the slightly positive carbon atom and is donated to it, forming a carbon-nucleophile bond. |
Once the nucleophile has made a bond with the carbon, what happens next? | The Carbon-Halogen bond is broken by heterolyctic fission (heterolyctic as BOTH of the electrons in the bond go to the SAME atom) and a new organic compound is formed |
Haloalkanes can be converted to alcohols using what aqueous solution? | Sodium hydroxide |
The reaction to form an alcohol from a haloalkane is very slow at room temperature, so to make sure a good yield is obtained, what conditions is the reaction done under? | It is heated under reflux |
What happens to the rate of hydrolysis as you go from C-F, to C-Cl, to C-Br, to C-I? | The rate increases as less energy is needed to break the bonds because they get weaker as you go down the halide group |
To measure the Rate of Hydrolysis reactions during nucleophillic substitution, what aqueous mixture is used? | Silver Nitrate |
What is formed when the halide ions produces react with the silver nitrate? | A silver-halide precipitate |
A haloalkane of 1-chlorobutane would produce a ______ coloured precipitate at a ________ rate | A haloalkane of 1-chlorobutane would produce a WHITE coloured precipitate at a SLOW rate |
A haloalkane of 1-bromobutane would produce a ______ coloured precipitate at a ______ rate | A haloalkane of 1-Bromobutane would produce a CREAM coloured precipitate at a MEDIUM rate |
A haloalkane of 1-Iodobutane would produce a ______ coloured precipitate at a ______ rate | A haloalkane of 1-Iodobutane would produce a YELLOW coloured precipitate at a RAPID rate |
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