AP Chemistry 2.5 Chemical Reaction Rates
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|AP Chemistry||Chemical Elements Are Building Blocks|
Chemical Reaction Rates
|Test Prep||AP Chemistry|
The purpose of a catalyst is to increase the rate of a reaction.
Meaning that a substance that inhibits a reaction is not a catalyst… [Catalyst added to a beaker]
So we can cross out D right off the bat.
And how does a catalyst increase a reaction rate? [A reaction rate graph]
By lowering the energy of an intermediate or transition state in the reaction mechanism.
This decreases the activation energy barrier, which makes the reaction go faster.
If only there were catalysts for doing that 8-page paper that’s due tomorrow, eh? [Woman scientist staring at a catalyst]
Just like your car, chemical reactions can go in the forward and reverse directions. [Car travelling up and down a hill]
The mechanism for the reverse direction is often just the forward mechanism, backwards.
That makes sense, right? [Car reverses up a hill]
So if a catalyst lowers the energy of a transition state, it can make both the forward and reverse
That means that the correct answer is B. Now don’t go get that paper done. [Person orders boy to finish his paper]
That was reverse psychology.
Is it working? [Boy working on his paper at his desk]