Download presentation
Presentation is loading. Please wait.
1
Kinetic Molecular Theory
The energy of motion is called kinetic energy. Molecules are always in motion. Therefore, all molecules have kinetic energy. The unique, random motion of a molecule over a period of time. Molecules move in a random pattern.
2
The Collision Model of Chemical Reactions
The collision theory states that in order for a chemical reaction to take place: Moving particles must collide with each other. Particles must collide with the right orientation (line up correctly). Particles must collide hard enough/with the right amount of energy.
3
The colliding of molecules is like the accidental colliding of vehicles on the road.
Sometimes vehicles collide when traveling a slow speeds. When this happens they simply bounce off of each other. At other times the vehicles collide at higher speeds and with more energy! In these cases the vehicles could stick together.
4
How can we increase the rate (speed) of reactions???
Two Ways to Make Reactions Occur More Quickly Increase the number of collisions. Increase the amount of collisions that are effective. How can we increase the rate (speed) of reactions???
5
Applying Prior Knowledge
1) How can we make this log burn faster? One large log. Chopped wood. By chopping the wood into smaller pieces we have increased the surface area that can be exposed to the flame. With an increase in the surface area there is an increased chance that reactants in a chemical reaction will come in contact with each other. Therefore, increasing surface area will increase the rate of a reaction.
6
2) Increase the temperature of the reactants.
What other things might we do in order to have chemical reactions occur more quickly? 2) Increase the temperature of the reactants. When you increase temperature, you increase the kinetic (moving) energy of the molecules. When molecules move about more quickly the chance of them colliding and the force with which they collide increases. Therefore, increasing temperature, increase the rate of a reaction.
7
3) Increase the concentration of the reactants.
What in the world is concentration? What do we have to add to the orange concentrate in order for us to be able to drink it? What will happen to the concentration of the orange juice as the ice cubes dissolve?
8
Concentrated solutions contain more atoms (molecules) than dilute solutions.
If a solution contains a lot more atoms (molecules) the chances of a collision occurring increases. Therefore, increasing concentration, increases the rate of a reaction.
9
4) Adding a catalyst. A catalyst is a substance that increases the rate of a chemical reaction without being consumed by the reaction. A catalyst is NOT a reactant. It just helps the reaction go faster by lining up the reactants together and gives them the correct orientation. It give the reactants an alternate pathway to react.
10
https://www.youtube.com/watch?v=OttRV5ykP7A ‘
How to Speed up Chemical Reactions (and get a date) Ted Video (4:55)
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.