Alkanes and Alkenes Flashcards
Catalyst and temperature needed for cracking
-Silica
-600-700C
Two reasons why cracking is important
-It forms more useful shorter-chain hydrocarbons, alkanes can be used for fuel
-Alkenes can be used to form polymers and plastics
Why is the impurity sulfur in crude oil dangerous environmentally?
-The sulfur is released into the atmosphere and reacts with water in the clouds forming sulfur dioxide
-Acid rain is formed and can damage natural habitats and wildlife
In terms of structure, why does C12H26 have a higher boiling point than C8H18
-It contains larger molecules and is a longer chain alkane
-It has stronger molecular forces and requires more energy to overcome
What environmental problems are created by the disposal of polymers?
-Polymers will remain in landfill indefinitely
-Unless burnt as they aren’t biodegradable
-Burning polymers releases toxic gases such as carbon dioxide into atmosphere.
What is crude oil?
A mixture of hydrocarbons
What is a fuel?
A substance that releases heat energy when burned.
Why are alkanes saturated?
Because they only have a single bond between the carbon atoms.
What is formed when an alkene reacts with bromine?
Dibromoalkanes
Results for alkane/alkene plus bromine water
Alkane - Solution remains orange as it doesn’t have a double bond so doesn’t react with it.
Alkene - Solution goes colourless
