1. What is a catalyst?
-A catalyst is any substance (atom, molecule, element, enzyme, etc) that increases the rate of a reaction without itself being consumed in the reaction. The catalyst therefore can be recovered, unchanged, after the reaction that it has sped up (or catalyzed) has completed. It speeds the reaction up by orienting the molecules to create better and more effective collisions.
Define a catalyst:
a. the sum of reactants and products
b. an enzyme
c. anything that increases the rate of reaction.
2. How does a catalyst effect the energy vs. time diagram?
Here is an example of an Energy/Time diagram of a reaction, with and without a catalyst.
This illustrates the speeding up of the reaction when a catalyst is added. Depending on the amount of the substance acting as a catalyst that you add to the reaction, that interval is how much lower your activation energy will be (w/ the reaction rate).
What is a catalyst's role in a reaction?
a. speed up
b. slow down
c. none of the above
3. Equilibrium and Catalysts
Catalysts do NOT effect the chemical equilibrium of the reaction in which they take part.
Perfect chemical eqilibrium is when the concentrations of all reactants and products remain constant as a function of time. (You should have previously learned about reactants and products previously). A catalyst merely affects (lowering) the activation energy required for a given reaction to proceed.
Here is a video that explains a little more about Catalysts:
Here are some other websites that may be useful (Including some with activities and demos):
http://www.flinnsci.com/Documents/demoPDFs/Chemistry/CF0255.01.pdf
A catalyst:
a. increases reaction rate
b. increases the activation energy
c. decreases the activation energy