Quiz

• Hydrocarbon


  Compounds composed ofonlycarbon and hydrogen
• Initiation


  Radicals are produced when acovalent bondisbroken homolyticallyusingUV radiationat ahigh temperature
• Propagation


  A radical reacts with a non-radical molecule, creating anew radicalthatgoes onto react with other non-radical(s)
• Termination


  Two radicals react to form a non-radical compound andendthechain reaction
• Haloalkanes


  Alkanes withoneor morehydrogen atoms replaced byhalogenatoms
• Photodissociation


  A bond isbrokenas a molecule absorbs aphotonof (sun)light energy
• Chlorofluorocarbons


  Molecules that have hadallof their hydrogens replaced bychlorine and fluorineatoms
• Stratosphere


  The layer of the atmosphere that is above the troposphere, whereC-Cl bondsin CFCs arebrokenin UV radiation to formchlorine radicalswhichcatalysethebreakdown of ozone
• Troposphere


  The lowest layer of Earth's atmosphere, by which point most of the high energy UV has alreadybeen absorbedin the ozone layer, meaningless CFC breakdown
• Bond enthalpy


  Theenthalpy change requiredto break a particular bond in1 moleofgaseousmolecules, determining thereactivityof a molecule
• Homogeneous catalyst


  A catalyst that is in thesame stateas all thereactantsand products in a reaction system
• Heterogeneous catalyst


  A catalyst that is in adifferent statefrom that of thereactants
• Collision theory


  Atoms, ions, and molecules mustcollidein order to react
• Rate of reaction


  Thechange in concentrationof a reactant or productper unit time
• Activation energy


  Theminimumamount of energy required tostarta chemical reaction
• Direction and KE


  The two things that need to be right for a collision to be successful
• Energy profile diagram


  A diagram that shows theenergy changesduring thecourse of a reaction
• Boltzmann distribution


  The distribution of energies of molecules in agasat aparticular temperature, usually shown as a graph.
• Total number of molecules


  What theareaunder a Boltzmann Distribution graph is equal to
• Energy and Money


  In industry, using a catalyst saves these two things
• Catalyst


  A substance thatincreases the rateof a chemical reaction by providing analternative reaction pathwaywith alower activation energy, whilst remainingchemically unchangeditself
• Homogeneous catalyst energy profiles

  Havetwoactivation energies (adouble humpin the diagram, with thesecond one lowerbut both smaller than with no catalyst) where theintermediatesare formed in the centre
• Ozone layer


  The protective layer in atmosphere that shields humans fromharmful UVradiation that causesskin cancer
• Photochemical smog


  When solid carbonparticulatesandozonemix in the troposphere we get atoxicpollution that can causerespiratory problemsin humans
• Gas concentrations


  These can be measured aspercentage concentrationsorparts per million
• Greenhouse effect


  Energy the Earth absorbs from the sun isre-emittedmainly asinfra-red(at a lower frequency than that of the sun) andtrappedin the atmosphere by the ozone layer
• Greenhouse gases


  Gases such as carbon dioxide and ozone in the atmosphere whichabsorb IR radiation, causing theirbonds to vibrateat aspecific frequency
• Quantised


  Electrons sit ondiscreteenergy levels, which can also be described as...
• Specific frequency


  When electronsabsorb/emitenergy, thediscrete energy levelsmean that this energy always has a...
• Oxygen free radicals


  If the double bond in an oxygen molecule breaks thanks to theright energybeingabsorbed, the covalent bond breaks
• Reversible reaction


  A chemical reaction in which the products canre-formthe original reactants
• Closed system


  A system in whichno matteris allowed toenter or leave
• Dynamic equilibrium


  Where therates of forwards and backwards reactions areequalbutno overall changein concentration
• Equilibrium constant (Kc)


  The constant in a reversible reaction that is specific for a certain temperature (increases when to right/decreases when to left) but is not affected by a change in concentration
• Fewest molecules of gas


  The side which theequilibrium positionwill shift to if there is achange in pressure
• Endothermic direction


  If there is anincreasein temperatureduring a reversible reaction, theequilibrium positionwill shift to aid the...
• Electrolysis


  Thebreaking downof a substance usingelectricity
• Molten


  ordissolved in solutionTheelectrolyteneeds to be anionic compoundthat is either...
• Free (moving) ions


  These are required for theconductionof electricity to take place in an ionic solution, which they get when either molten or dissolved in solution
• Flow


  Moltenordissolved ioniccompounds also canconductelectricity because they are able to do this