COLLISION THEORY Surface Area and Reaction Rate
Matter Particles Solids Liquids Gases is made of Which are arranged differently in
Simple Collision Theory
How can we increase high energy collisions? Increase surface area Increase Temperature Increase concentration
Increase temperature Particles have more energy. Particles move faster. Particles have MORE EFFECTIVE COLLISIONS PER SECOND. Low Temperature High Temperature
Increase concentration If a reactant is more concentrated… … particles are more crowded… … so there are MORE EFFECTIVE COLLISIONS PER SECOND! Low concentration High concentration
Increase surface area If surface area is high (as in a powder), less particles will be trapped in the center. Low surface areaHigh surface area So there are MORE EFFECTIVE COLLISIONS per second.
Smaller particles have a bigger surface area than larger particle for the same mass of solid.
Bread and Butter Theory Take a loaf of bread and cut it into slices. With each new slice, you get an extra surface to spread butter. The thinner the slices, the more slices you get and so the more butter you can put on them. By chewing your food you increase the surface area so that digestion can go faster.