organic chem I

Question 1

Reaction of Alkenes with Hydrogen

Answer 1

Change in functional group: alkene  alkane
Reagent: hydrogen
Conditions: Nickel Catalyst
Type of reaction: Addition/Reduction

Question 2

Reaction of Alkenes with bromine/chlorine

Answer 2

Change in functional group:
alkene  dihalogenoalkane
Reagent: Bromine (dissolved in organic solvent)
Conditions: Room temperature (not in UV light)
Mechanism: Electrophilic Addition
Type of reagent: Electrophile, Br+ Type of Bond Fission: Heterolytic

Question 3

Reaction of Hydrogen Bromide with alkenes

Answer 3

Change in functional group:
alkene halogenoalkane
Reagent: HCl or HBr
Conditions: Room temperature
Mechanism: Electrophilic Addition
Type of reagent: Electrophile, H+ Type of Bond Fission: Heterolytic

Question 4

alkene to diol

Answer 4

Reagent: KMnO4
in an acidified solution
Conditions: Room temperature
Type of reaction: Oxidation
Observation: purple colour of MnO4
-
ion will
decolourise to colourless

Question 5

Reaction of Bromine Water with Alkenes

Answer 5

Reagent: Bromine dissolved in water
Conditions: Room temperature
Type of reaction: Addition
Observation: Orange colour of bromine water
will decolourise to colourless

Question 6

hydration of alkenes

Answer 6

add water to form alcohols

Essential Conditions
High temperature 300 to 600°C
High pressure 70 atm
Catalyst of concentrated H3PO4

Question 7

nucleophilic sub w ammonia

Answer 7

Change in functional group: halogenoalkane 
amine
Reagent: NH3 dissolved in ethanol
Conditions: Heating under pressure in a sealed
tube
Mechanism: Nucleophilic substitution
Type of reagent: Nucleophile, :NH3

Question 8

halogenoalkane to alkene

Answer 8

Reagents: Potassium (or sodium) hydroxide
Conditions: In ethanol ; Heat
Mechanism: Elimination
Role of reagent: Base, OH

Question 9

alcohol to alkene

Answer 9

Reagents: Concentrated phosphoric acid
Conditions: warm (under reflux)
Role of reagent: dehydrating agent/catalyst
Type of reaction: acid catalysed elimination