Reactions Flashcards
How do alkenes react via?
Alkenes react via addition reactions. As alkenes have the functional group C=C, they react in similar ways.
How do addition reactions work?
The carbon-carbon double bond in an alkene will open up to leave a single bond a new atom is added to each carbon.
What is a hydrogenation reaction - and how does it work?
Hydrogen can react with a C=C double bonded carbon to open up the double bond, and form the equivalent, saturated alkane.
How is an alkene reacted in a hydrogenation reaction?
The alkene is reacted with hydrogen in the presence of a catalyst.
What is a hydration reaction?
When alkenes react with steam, water is added across the double bond and an alcohol is formed.
What is an example of a hydration reaction?
Ethanol can be made my mixing ethene with steam and then passing it over a catalyst.
What is a halogen reaction?
Alkenes react in addition reactions with halogens like bromine, chlorine and iodine.
What is the result of a halogen reaction called
dihaloalkanes
Are dihaloalkanes saturated or not?
They are saturated, with the C=C carbons each becoming bonded to a halogen atom.
What is an example of a dihaloalkane.
Bromine and ethene react together to form dibromoethane.
What is the test for saturation?
The addition of bromine to a double bond can be used to test for unsaturated compounds.
What happens if orange bromine is added to a saturated compound?
When orange bromine solution is added to a saturated compound, like an alkane, no reaction will happen and it will stay orange.
What happens if orange bromine is added to an unsaturated compound.
If orange bromine solution is added to an unsaturated compound, like an alkene, the bromine will quickly add across the double bond making a colourless dibromo-compound - so the bromine solution will be decolourised.
