AP Chemistry 3.3 Chemical Reaction Rates

AP Chemistry 3.3 Chemical Reaction Rates. Which of the following is true regarding rates of chemical reactions?

APAP Chemistry
AP ChemistryChemical Reaction Rates
LanguageEnglish Language
Test PrepAP Chemistry

Transcript

00:23

This question is about reaction rates, by which we don’t mean how long it takes you [Man on stage telling jokes]

00:28

to start laughing after we tell a hilarious joke.

00:30

We’re talking about chemistry here, guys.

00:33

Get with it.

00:34

There are a few tried and true ways to speed up chemical reaction rates. [Scientist transferring substance to a beaker and it explodes]

00:38

Let’s imagine that each time two of these red molecules react, they create one blue [Red molecules collide and create blue molecule]

00:43

molecule.

00:44

To increase the reaction rate, we could increase the concentration of the reactants.

00:48

This would lead to more collisions between the reacting molecules, which would cause [Molecules colliding]

00:53

the reaction rate to increase.

00:55

That’s pretty straightforward, right?

00:57

Another way we could increase the reaction rate would be to use a catalyst.

01:01

Because that’s the whole point of catalysts.

01:02

Seriously.

01:03

That’s all they do.

01:04

They’re kind of a one-trick pony.

01:07

Catalysts work by decreasing activation energy barriers so molecules that collide are more [Catalysts in a beaker with molecules]

01:13

likely to react.

01:14

And if you’ve ever witnessed two angry people bumping into each other, you’ll know that [Two guys bump into each other]

01:18

people that collide are also pretty likely to react.

01:22

And last, but not least, we could also speed up a reaction by turning up the heat. [Fire burning]

01:28

Besides keeping us nice and toasty, increasing the temperature can speed up a chemical reaction

01:34

by giving reacting molecules more kinetic energy.

01:37

This makes them collide more frequently and with more energy, so they’re more likely [Molecules colliding frequently]

01:41

to overcome the activation barrier and react.

01:44

Which is why if you go to a hot yoga class, you’ll see a lot of people falling over [Boy in yoga class falls over]

01:48

each other.

01:49

That’s how that works, right?

01:50

Hey, that last method sounds really similar to answer B, which says that chemical reaction

01:55

rates can be increased by increasing the temperature.

02:00

And wouldn't you know it, the answer is B. Did you get it right? [Man with hair on fire running and screaming]

02:03

We bet you did.

02:04

You are on fire today. [Man uses fire extinguisher on mans head]