Flashcards
ALKENES
Cards in this deck (10)
- 1GENERAL FORMULA FOR ALKENESCN H2N
- 2CHEMICAL PROPERTIES OF ALKENESSAME AS ALKANES
- 3WHAT KIND OF REACTION MECHANISM DO ALKENES UNDERGO?ELECTROPHILIC ADDITION. ETHENE HAS A HIGH ELECTRON DENSITY DUE TO THE PI ELECTRONS IN THE DOUBLE BOND. THIS CAUSES THE BROMINE APPROACHING IT TO BECOME POLARIZED. A LOOSE ASSOCIATION FORMS BETWEEN ETHENE AND BROMINE. THE NEGATIVE CHARGE FROM THE DOUBLE BOND MOVES TOWARDS THE BROMINE WHILE THE ELECTRONS FROM THE BR-BR BOND MOVES TOWARDS THE NEGATIVELY CHARGED BR ATOM (HETEROLYTIC FISSION). THIS RESULTS IN THE FORMATION OF A CARBOCATION AND BR ION. THE CARBOCATION IS QUITE UNSTABLE AND RAPIDLY REACTS WITH THE BR ION.
- 4COMBUSTION OF ALKENESALKENES BURN IN OXYGEN TO GIVE CARBON DIOXIDE AND WATER.
- 5REACTION WITH HALOGENALKENES REACT WITH HALOGENS UNDER NORMAL CONDITIONS TO FORM DIHALOGENOALKANE.
- 6REACTION WITH HYDROGEN HALIDESALKENES REACT WITH GASEOUS HYDROGEN HALIDE DISSOLVED IN AN INERT SOLVENT IN THE COLD TO FORM A HALOGENOALKANE.
- 7REACTION WITH HYDROGENGASEOUS ALKENES REACT WITH HYDROGEN GAS IN THE PRESENCE OF A FINELY DIVIDED NICKEL CATALYST ON AN INERT MATERIAL TO FORM AN ALKANE.
- 8REACTION WITH WATERALKENES REACT WITH WATER IN THE VAPOUR PHASE AT HIGH TEMPERATURES(330C) AND PRESSURE(600ATM), IN THE PRESENCE OF PHOSPHORIC ACID CATALYST TO FORM AN ALCOHOL.
- 9REACTION WITH COLD, ALKALINE KMNO4ALKENES REACT RAPIDLY WITH COLD, ALKALINE KMNO4 TO FORM A DIOL. THE PURPLE MANGANATE TURNS BROWN.
- 10REACT WITH HOT CONCENTRATED KMNO4ALKENES ARE OXIDISED TO CARBONYLS THEN FURTHER OXIDISED TO CARBOXYLIC ACIDS WHEN HEATED UNDER REFLUX. OXIDATIVE CLEAVAGE OF THE DOUBLE BOND OCCURS.
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- a-levels Chemistry (organic chemistry) Flashcards on ALKENES, created by hannie edward on 06/05/2015.
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- hannie edward
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