1 / 11

Factors affecting rxn rates #3

Factors affecting rxn rates #3. http://www.youtube.com/watch?v=5tFy9bOLsxw Iron Combustion!. Increasing the Rate of Reactions. 1. Increasing temperature. 2. Increasing reactant concentration.

Download Presentation

Factors affecting rxn rates #3

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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Factors affecting rxn rates #3

  2. http://www.youtube.com/watch?v=5tFy9bOLsxw Iron Combustion!

  3. Increasing the Rate of Reactions 1. Increasing temperature 2. Increasing reactant concentration 3. Adding a catalyst(aninhibitor decreases) triggers a reaction rate to increase; participates in the reactions but comes out the same way it went in. 4. Nature of the reactant(changing a reactant for a more reactive one) • Increasing the pressure • Increasing the surface area – only for heterogeneous rxns!

  4. Homogeneous Vs Heterogeneous Reactions A homogeneous reaction is one where all the reactants are in the samephase. They are fast due to thorough mixing and manycollisions! H2(g) + O2(g) → AgNO3(aq) + NaCl(aq) → same- only look at reactants!

  5. Factors that Affect the Reaction Rate Heterogeneousreactants are in two or more different phases Slow due to poor mixing and fewer collisions Zn(s) + 2HCl(aq) → Fe(s) + O2(g) →

  6. heterogeneous Classify as Homogeneous or Heterogeneous: 2.                   Ag+(aq)  +  Cl (aq)          →       AgCl  (s)                    homogeneous 1.  Zn (s)  +  2HCl (aq)       →       H2(g)  +  ZnCl2  (aq) homogeneous 3.                   H2(g)    +  F2(g)        →              2HF (g)                                     

  7. What reactions are faster? ( in general ) 1. Homo’s are fasterthan hetero’s. 2. FastestSlowest (aq) (g and l) (s) only reactants 3. Simple ionicare fastest -no bonds to break- double replacement AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq) Becomes: Ag+ + NO3- + Na+ + Cl- → AgCl(s) + Na+ + NO3- Fast Ag+ + Cl- → AgCl(s) Fast simple ionic!

  8. Describe each Pair of reactions as faster or slower. 2NaClO3(aq) + F2(aq) → 2NaF(aq) + 3O2(g) + Cl2(g) Faster Homo 3H2(g) + N2(g)  2NH3(g) Homos are fast- more collisions Aqueous reactions are fasters than gaseous. Homo

  9. Describe each Pair of reactions as faster or slower. Zn(s) + 2HCl(aq)  H2(g) + ZnCl2(aq)  Faster because aq ions: 1. close proximity in soln 2. ability to move through solvent 3. strong +/- interactions. Hetero C(s) + O2(g)  CO2(g) Hetero

  10. State five ways to increase the rate of this reaction. Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq) 1. Increase temperature 2. Increase [HCl], add more Mg 3. Add a catalyst 4. Increase surface area (powder Mg) 5. Agitate

  11. Hebden, p 7. Exercises 10 – 11; p 8. Exercises 12 – 14; p 9. Exercises 15 – 16 AND 17. (Read page12 on Collision Theory to fill in the blanks for tomorrow’s lecture)

More Related