Chemistry- Product from Crude Oil

kushagramodi56's version from 2015-04-16 15:51


Question Answer
What are alkenesThe are unsaturated structures containing mixtures of hydrocarbons
What is meant by unsaturated structuresHave at least 1 double bond
What is the general formula for alkenesCnH2n
What is crackingBreaking down large hydrocarbons into small hydrocarbons in a steel vessel called a cracker
How does cracking occurIt involves heating the hydrocarbon strongly and passing the vapours over hot catalyst of aluminium oxide/ ceramic pot
How do you distinguish between an alkane and an alkeneBy using bromine water. If it is an alkane it will change from orange- brown to colourless. If it is an alkene, it will stay orange- brown.
What are monomersSmall molecules able to combine with other similar molecules to form a long molecule called a polymer
What are polymersSubstances containing very long molecules made of smaller molecules called monomers
What is polymerisationProcess where monomers join together to form large polymer molecules
What are the atoms within a polymer held byStrong covalent bonds
What are the properties of a polymer determined byThe strength of bonds and forces between the polymer chains. The monomer the polymer is made from. The condition the polymers are made in
Properties of thermosoftening plasticsWeak intermolecular forces. When heated, become soft + runny. Flexible. High tensile strength. Low melting point.
Properties of thermosetting plasticsStrong cross links. Upon heating, stays hard. High melting points. Rigid and not flexible.
How is low density poly(ethene) formedUnder high temp. and high pressure
How is high density poly(ethene) formedUnder low temp., low pressure and with a catalyst
Properties of low density poly(ethene)Weak intermolecular forces and flexible
Properties of high density poly(ethene)Strong intermolecular forces and rigid
What are designer polymersPolymers designed to have ideal properties for a specific use
What are smart polymersPolymers that change in response to changes in the environment. They are able to remember their old shape.
What does biodegradable meanMicro-organisms are able to break it down