07 - Kinetics
Bookmark this page

7.1 Rates of reaction

7.1.1 : Rate of reaction is concerned with how quickly a reaction reaches a certain point (not to be confused with how far a reaction goes...ie equilibrium).

7.1.2 : Interpretation of rate graphs. Reaction rater graphs will generally be graphed with time on the x-axis and some measure of how far the reaction has gone (ie concentration, volume, mass loss etc) on the y-axis. This will generally produce a curve with, for example, the concentration of the products approaching zero.

7.2 Collision theory

7.2.1 : Collision theory -- reactions take place as a result of particles (atoms or molecules) colliding and then undergoing a reaction. Not all collisions cause reaction, however, even in a system where the reaction is spontaneous. The particles must has sufficient kinetic energy, and the correct orientation with respect to each other for the two to react.

7.2.2 : Higher temp -> greater average kE -> faster reaction. Higher concentration -> more collisions -> faster reaction. Catalysts -> lower activation energy / greater probability of proper orientation -> faster reaction. In hetrogenious reactions (where the reactants are in different states) the size of the particles of a solid may change reaction rate, since the surface is where the reaction takes place, and the surface area is increased when the particles are more finely divided...(therefore smaller solid particles in a hetrogenious reaction -> faster reaction).

7.2.3 : Most reactions involve several steps, which can be individually slow of fast, and which, all together, make up the complete reaction. The slowest of these steps is called the rate determining step, as is determines how fast the reaction will go. It is also not necessary that all the reactants are involved in ever step, and so the rate determining step may not involve all the reactants. as a result, increasing their concentration (for example) of a reactant which is not involved in the rate determining step will not change the overall reaction rate.

Other Notes in this Category

1. 01 - Stoichiometry
2. 02 - Atomic Theory
3. 03 - Periodicity
4. 04 - Bonding
5. 05 - States of Matter
6. 06 - Energetics
7. 07 - Kinetics
8. 08 - Equilibrium
9. 09 - Acids and Bases
10. 10 - Oxidation and Reduction
11. 11 - Organic Chemistry
12. 12 - Atomic Theory
13. 13 - Periodicity
14. 14 - Bonding
15. 15 - States of Matter
16. 16 - Energetics
17. 17 - Kinetics
18. 18 - Equilibrium
19. 19 - Acids and Bases
20. 20 - Oxidation and Reduction
21. 21 - Organic Chemistry

Didn't find this useful?

• Visit Coursework.Info for over 14,000 GCSE, A-Level and University Essays