rates of reactions part 2 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Rates of Reactions – Part 2 PowerPoint Presentation
Download Presentation
Rates of Reactions – Part 2

Loading in 2 Seconds...

play fullscreen
1 / 16

Rates of Reactions – Part 2 - PowerPoint PPT Presentation


  • 90 Views
  • Uploaded on

Rates of Reactions – Part 2. Factors affecting the rate of reaction. The surface area The concentration of the reactant The temperature at which the reaction is carried out The use of a catalyst The influence of light. 4. Rate of Reaction – Effect of Catalyst.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Rates of Reactions – Part 2


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
factors affecting the rate of reaction
Factorsaffectingthe rate ofreaction
  • The surfacearea
  • The concentrationofthereactant
  • The temperatureatwhichthereactioniscarried out
  • The useof a catalyst
  • The influenceoflight
4 rate of reaction effect of catalyst
4. Rate ofReaction – EffectofCatalyst

Hydrogen peroxidewater + oxygen

Powderedmanganese IV oxide MnO2isaddedas a catalyst.

The morefinelygroundupthemanganeseoxideisthefasterthereactiongoes.

The massofthemanganeseoxideremainsthe same.

Itis a catalyst.

effect of catalyst
EffectofCatalyst

The morecatalystyouusethefasterthereaction.

The type ofcatalystyouuse will effectthereaction.

definition of a catalyst
Definition of a Catalyst

A catalystis a substancethatincreasesthe rate of a chemicalreaction. The catalystremainschemicallyunchanged.

how does a catayst work
Howdoes a cataystwork?
  • The provide a surface on whichothermoleculesoratomscanreact.
catalysts in industry
Catalysts in Industry
  • Catalystsareveryusefulasyouonlyneed a smallamounttodramaticallychangethe rate of a reaction.
  • The catalystis not usedup so canbeusedagainandagain.
  • Used in theproductionofpolythene, painkillers, fertilizersandfabrics.
  • The processestomakethesecompounds, withoutcatalysts, wouldneedmuchmoreenergyandbemuchmorecostly.
catalytic convertors
CatalyticConvertors
  • Used on carstoreducepollution.
  • Car exhaustsproduce CO, NO andunburnthydrocarbons.
  • The catalyticconvertorconvertsthesetolessharmfulproducts CO2, N2andwater.
  • The catalyticconvertorremovespollutingoxidesandcompletestheoxidationofunburnthydrocarbons.
catalytic converters
Catalytic Converters

Rhodium andplatinum – preciousmetalsused

biological catalysts
Biological Catalysts
  • Living cells also producecatalysts, theseareproteinmoleculescalledenyzmes.
  • Characteristics;
    • Enzymes areproteins
    • Veryspecific – controlonlyonereaction
    • Temperature sensitive – stopworkingabove 45oC
    • pH sensitive – workbestat pH 7
enzymes in i ndustry
Enzymes in Industry
  • Biological washingpowdersuseenzymestoremovebiologicalstains(sweat, blood, food).
  • The enzymes break down protiensandfats.
  • Becausetheenzymesaretemperaturedependenttheyneed a washofnomorethan 40oC
surface catalysts and collision theory
SurfaceCatalystsandCollisionTheory
  • Onemain type ofcatalystworksbyabsorbingthereactantmoleculesonto a solid surface.
  • This processofadsorptionbringsthereactingmoleculesclosertogether.
nickel catalyzed hydrogenation
Nickel CatalyzedHydrogenation
  • Finelydividednickelisusedas a catalysttoadd hydrogen tounsaturatedhydrocarbons.
collision theory
CollisionTheory
  • If a reactiononlyoccurswhenparticlescollidewiththesurfaceof a solid….
    • Thenitfollowsthatthemoresurfaceareayouhave, themorecollisionsyouhave, thefasterthereactionis.
  • This also appliesif;
    • solutionsaremoreconcentrated
    • Gases aremorecompressed
  • Increasingthetemperatureincreasesthespeedtheparticlesaremovingagainincreasingtheprobabilityofcollision.
activation energy
ActivationEnergy
  • Not everycollisionproduces a reaction.
  • A certainamountofenergyneedstobepresentto break thebonds, EA
  • A catalystincreasesthe rate ofreactionbyreducingthe EA
activity
Activity
  • Page 216
  • Exercise 7.4 on worksheet
  • Read aboutphotochemicalreactionsand do questions on page 218