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Name: ______________________________________

Date: ________________________

Student Exploration: Collision Theory
NCVPS Chemistry Fall 2014
Vocabulary: activated complex, catalyst, chemical reaction, concentration, enzyme, half-life,
molecule, product, reactant, surface area
Prior Knowledge Questions (Do these BEFORE using the Gizmo
...
Suppose you added a spoonful of sugar to hot water and another to ice-cold water
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2
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Which form of wood will catch fire more easily? Wood shavings
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Reactants are substances that
enter into a reaction, and products are substances
produced by the reaction
...

You will need blue, green, and orange markers or colored
pencils for the first part of this activity
...
Look at the key at the bottom of the SIMULATION pane
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Reactants:

A

Products: A
B

B

2
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What do you see? The first three were reactants A and B but reactants
A took part of reactants B and then turned into products A and B
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com on 09-15-2022 15:03:01 GMT -05:00

https://www
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com/file/44100622/collision-theory-gizmoDONEdoc/

Get the Gizmo ready:
Activity A:
Temperature

 Click Reset (
)
...
0 mol/L, the Catalyst concentration is set to
0
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Question: How does temperature affect the rate of a chemical reaction?
1
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View the animation with No catalyst selected
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When two reactant molecules meet, they form a temporary structure called an activated
complex
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2
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Set the Temperature to 0 °C and the Simulation
speed to its maximum setting
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A
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They slow down
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Now set the Temperature to 200 °C
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C
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3
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Click the zoom out button (

) until you can see the whole

graph
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4
...

(Activity A continued on next page)

This study source was downloaded by 100000789634174 from CourseHero
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Gather data: Click Reset
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With the
Temperature set to 200 °C, click Play
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Record the half-life time in the first space of the table below
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(Note: To get exact
times, you can refer to the TABLE tab
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Calculate: Calculate the mean half-life for each temperature
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(Hint: To get an exact mean, first convert each time to seconds by multiplying the minutes
value by 60 and adding this to the seconds
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Convert the answer back to minutes and seconds
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Analyze: What do your results indicate? As the temperature goes down, the time goes up
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Draw conclusions: For two molecules to react, they must collide at just the right angle and
with enough energy to break the original bonds and form new ones
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9
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This can be done by
putting the paper over a flame
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 Check that the Catalyst concentration is set to
0
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 Set the Temperature to 200 °C
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The
surface area of a solid is a measure of how much of the solid is exposed to other substances
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Question: How do surface area and concentration affect reaction rates?
1
...
How does this change
the amount of Reactant B molecules that are exposed to Reactant A?
They are moving around and not staying on one side
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Predict: How do you think increasing the surface area will affect the rate of the reaction?
It will make the reaction go faster
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Gather data: Set the Reactant concentration to 2
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Use the Gizmo to measure
the half-life of the reaction for each surface area setting
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) Then, calculate the mean half-life for each setting
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Analyze: What do your results indicate? Most surface area speeds up the process of the
chemical reaction
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Explain: Why does the reaction proceed more quickly when the surface area is
increased?
The reactants B are spread out so they don’t have to wait for a reactant A to come get them
and they are moving
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com on 09-15-2022 15:03:01 GMT -05:00

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Activity B (continued from previous page)
6
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Move the Reactant concentration slider back and forth
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7
...


8
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Gather data: Make sure the Temperature is 200 °C and the Surface area is Maximum
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(Note that the
number of reactant molecules changes with each concentration
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Trial

0
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8 mol/L

1
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6 mol/L

2
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What is the mean class time for a concentration of 0
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0 mol/L?
Mean for 0
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0 mol/L: ?

10
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11
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Based on what you have learned in activity A and activity B,
what are three things you could do to make the reaction occur more quickly?
Increases the temperature, surface area, and the reactant concentration
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com on 09-15-2022 15:03:01 GMT -05:00

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com/file/44100622/collision-theory-gizmoDONEdoc/

Activity C:

Get the Gizmo ready:

Catalysts

 Click Reset (

)
...
The catalyst
molecules are not changed by the reaction and can be reused over and over again
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Observe: Select the ANIMATION tab
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A
...

B
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Many catalysts have a special shape that allows them to bind to specific reactant molecules
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Predict: How do you think catalysts will affect the rate of a chemical reaction? Increase
the rate
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Gather data: On the CONTROLS pane, set the Reactant concentration to 2
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Measure the half-life for each
given catalyst concentration
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Trial

4
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00 mol/L

0
...
10 mol/L

0
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(Activity C continued on next page)

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Explore: Set the Catalyst concentration to 0
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Click Play, wait for 10 minutes of simulated time, and click Pause
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What happens? 6 products were formed
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Click Reset, set the Catalyst concentration to 0
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After 10
simulated minutes, click Pause
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C
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6
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7
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For example, the enzyme pepsin helps to break down protein
molecules in your stomach
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