1. Reaction Rates
& Collision Theory

2. Collision Theory
In order for a chemical reaction to take place effective collisions must occur between reactants.

4. AND the molecules must be in the
Collisions are only effective if
they have enough kinetic energy to overcome the activation energy
AND the molecules must be in the
proper orientation

6. 5 factors that determine the rate (speed) of reaction

7. 1.) Nature of the Reactants
Ionic reactions happen faster than covalent
Solutions(aq) & liquids(l) react faster than solids(s)

8. 2.) Temperature
increase in temperature increases the rate chemical reactions
WHY?
the KE of the particles increases, and effective collisions are going to happen more often

9. 3.) Concentration of Reactants

10. Increasing pressure of GAS
Squeezes the molecules closer together and increases the concentration.
Molecules closer together increases the number of effective collisions.

11. but you can increase its surface area
Sometimes you can’t change the concentration of the substance
but you can increase its surface area

12. 4.) Increasing Surface Area
Smaller particle size allows more
of the reactant to be exposed . . .
and therefore ??????

13. Enzymes are biological catalysts
5.) Adding a Catalyst
A catalyst is a substance that speeds up a chemical reaction without being changed itself.
Enzymes are biological catalysts

14. do not change Adding a catalyst decreases the activation E Energy
Initial E and final E do
not
change
Energy

15. THE END
!!!!!!