Reaction Rates

Chemical Reaction Rates Chemical reactions can occur at different speeds Some are fast (like explosions) Some are slower Yeast and CO2 Can we change the rates of reactions?

Reaction Rates Chemical reaction speed can be affected by several factors: Temperature Surface area Concentration

Temperature Most reactions proceed faster at higher temperatures. Why? Particles are moving faster, so they collide more and have more of a chance to react.

Surface Area Surface area is the area (length x width) of an object The smaller an object is, the more surface area it has compared to its volume. If you put a whole potato in water to boil, how much of it is in contact with the water? What if you cut it up? Would this speed up its cooking time? Why?

Concentration The concentration of a substance refers to how much of it there is in a given volume. Kind of like density! Typically, higher concentrations of reactants react faster than lower concentrations.

Catalysts A catalyst is a substance that is used to speed up reactions One specific type of catalyst is called an enzyme Ex: digestive enzymes help your body chemically break down food.