Collision Theory
Chemical Kinetics
Factors Affecting Reaction Rate
Experiments
Random
100
Describe the difference between a collision and an effective collision
An effective collision is a collision that happens with the...
1. right orientation
2. right amount of energy
100
Chemical kinetics is the study of the ____________ of a reaction.
speed
100
What are the four factors that influence reaction rate?
1. temperature
2. concentration
3. catalyst
4. surface area
100
If you put an eggshell in vinegar, it dissolves. Ms. Gelfand wanted to carry out this experiment, and obtained the following results. Which trial had the fastest reaction rate?
Trial 3
100
Who was the first woman to win a Nobel Prize?
Marie Curie (first in Physics, then Chemistry)!
200
The amount of energy needed to make a reaction happen is known as...
activation energy
200
In the context of collision theory, what is reaction rate referring to?
the frequency of effective collisions
200
I run a reaction at 25oC. The reaction isn't going as planned, so I increase the temperature to 30oC. Will that increase or decrease the rate of the reaction? Explain.
increase
200
Identify the trial that had the fastest reaction rate. Based on the information in the data table, why did this have the fastest reaction rate?
higher temperature = more effective collisions
200
What is the largest organ in the human body?
The skin!
300
Stirring a reaction mixture will...
a. increase the number of collisions
b. decrease the number of collisions
c. not change the number of collisions
d. more information is needed
a. increase the number of collisions
300
Think of another word or phrase that has the word "kinetic" in it. How does that relate to chemical kinetics?
Kinetic energy is the energy of things with speed (in motion).
Chemical kinetics studies the speed of a reaction
300
Decreasing the concentration of a given reactant in a reaction will...
a. increase the reaction rate
b. decrease the reaction rate
c. not change the reaction rate
d. need more information
b. decrease the reaction rate
300
If you put an eggshell in vinegar, it dissolves. To test whether this experiment really works, Ms. Gelfand put an egg shell with an area of 5 cm2 in vinegar. It dissolved, but very slowly. Suggest one way Ms. Gelfand can speed up the reaction without changing the temperature of the vinegar-eggshell mixture.
break the eggshell up into smaller pieces
300
Originally, Amazon only sold what kind of product?
Books!
400
Ms. Gelfand mixes the solid form of substance A with the solid form of substance B and observes no reaction. When Ms. Gelfand mixes a solid form of substance A with a liquid form of substance B, a reaction occurs. Why?
for a reaction to happen, we need a collision. solid substances are fixed and rarely move (unlike gases and liquids), so there will be very few, if any, collisions
400
Draw a graph depicting activation energy.
400
I want to see what happens when I put an alka seltzer tablet in a glass of orange juice. I put a whole alka seltzer tablet into a glass of orange juice, but the reaction isn't running as quickly as I want it to. Using the concept of surface area, how can I increase the rate of the reaction?
break the alka seltzer tablet into smaller pieces
400
The longer it takes for a reaction to complete, the [higher/lower] the reaction rate.
LOWER
long reaction = slower to complete = slow reaction rate
400
What is the only letter of the alphabet not to appear in the name of any US state?
Q
500
Come up with an analogy for collision theory (must describe both requirements for an effective collision). Explain it, act it out, draw it, whatever you want! Be creative.
Let's see what you came up with!
500
Why might we want a reaction to proceed quickly?
medicines, studying reactions that typically take a long time
500
How do catalysts speed up reactions?
By lowering the activation energy!
500
Ms. Gelfand sets up a reaction to show her 1B, 2B, and 3B class. She doesn't want to have to set up the reaction three separate times, so she thinks about how she can slow the reaction down enough for her 1B, 2B, and 3B periods to see the same reaction. What would you suggest Ms. Gelfand do to accomplish this goal?
decrease the temperature of the reaction
decrease the surface area of reactant(s)
decrease the concentration of reactant(s)
500
What ion charge and number does Selenium form?
-2