Hydrocarbons and Plastics Flashcards
what is a homologous series
a homologous series is a series of molecules with the same general formula and similar chemical properties
What is a hydrocarbon?
A hydrocarbon is a molecule that contains only carbon and hydrogen atoms.
what are alkanes
alkanes are a homologous series of hydrocarbons with single carbon to carbon bonds.
what is the general formula for the alkanes
CnH2n+2
what is an isomer
Isomers have the same molecular formula but different structural formula-same number of atoms arranged in different ways.
what is a cycloalkane
a cycloalkane is another hydocarbon family. The carbon atoms are all joined together to form a ring.
what is the general formula for a cycloalkane
CnH2n
What are the alkenes
the alkenes are another hydrocarbon family. They must posses a carbon to carbon double bond. The name ends in ene
why cant you have a branch on ethene or propene
it would just be a continuation of the chain
why dont you call ethene “eth-1-ene” or propene “prop-1-ene”
because theres only 1 position for the double bond
what are the physical properties of hydrocarbons?
at room temperature they are usually clear liquids.
they are highly flammable
they smell like petrol
a use of them is fuels
explain the term saturated
it means all their carbon to carbon bonds are single bonds
explain the term unsaturated
it means it contains a carbon to carbon double bond - it will decolourise bromine solution
what happens as the chain length increases
the melting and boiling point increase - the intermolecular forces become stronger.
what will happen when you add bromine solution (halogen) to an unsaturated hydrocarbon
the unsaturated hydrocarbon (alkene) will undergo an addition reaction with the bromine - the bromine would rapidly decolourise
what hydrocarbons are saturated and unsaturated
saturated - alkane, cycloalkane
unsaturated - alkene
when a hydrocarbon is burned what will the products be
water (H20) + carbon dioxide (CO2) (if there isnt a plentiful supply of oxygen it will produce carbon monoxide)
what is the hydrocarbon reacting with when it is burned ( combustion)
oxygen
what is an addition reaction
when a chemical is added across the double bond of an alkene. the unsaturated molecule becomes saturated.
what is the name of an addition reaction with water
hydration
what is the name of a addition reaction involving hydrogen
hydrogenation reaction
what is the name of an addition reaction involving a halogen
halogenation
what is a plastic
a plastic is a substance which can be shaped or moulded into solid objects
they are synthetic (made by scientists)
what are plastics usually made from
plastic are usually made from chemicals found in crude oil-mostly alkenes
what can plastics be used for
they can be used as synthetic fibers such as nylon and gore-tex
what is meant by a synthetic fibre
fibre made from plastic/polymer
what is meant by thermoplastic and thermosetting
thermoplastic means it softens under heat, thermosetting means it hardens under heat.
describe how the properties of plastics relate to their uses
hardened plastics for milk cartons
a flexible plastic for cling film
soft plastic for carrier bags
thermosetting plastics for kettles/pot handles
what is meant by biodegradable
biodegradable means something can rot naturally. plastics are not biodegradable
describe what happens when a plastic is recycled
the plastic is broken apart and shredded into flakes or pellets and cleand. the flaked or pellets are then sent to manufacturers of plastic goods
what are some examples of what recycled plastics can be converted to
t-shirts, plastic lumber, toys, compost bins, rulers
what happends when plastics are burned
they release toxic gasses. (carbon monoxide)
PVC releases hydrogen chloride
HCN releases hydrogen cyanide(if its plolyurethane)
what are plastics made from?
a monomer
the plastic is called the polymer and it takes its name from the monomer
what is addition polymerisation
it is the process to make polymers from monomers
Polymerisation is when the double bond in alkenes opens up to allow another alkene to join
why do the monomers need to have a carbon to carbon double bond
you need a carbon to carbon double bonds for an addition reaction to take place (addition polymerisation)
