Chemistry
Ms. Boon
Name: ______________
Period: ____ Date: ______
Gases - Day 2: The Kinetic-Molecular Theory of Gases
Balloon in a Bottle Activity: Complete this activity with a partner. Safety: Only one person may blow up the balloon.
1.
Blow up the balloon. Draw a picture and answer the questions in box 1. Is it easy or difficult to blow up the balloon? Why?
2.
Put the round part of the balloon inside your 2 L bottle. Roll the neck of the balloon over the mouth of the bottle.
3.
Blow up the balloon in a bottle. Draw a picture and answer the questions in box 2. Is it easy or difficult to blow up the balloon? Why?
Box 1: Balloon without a bottle
4.
Box 2: Balloon in a bottle
What causes the balloon to expand?
______________________________________________________________________________________________________________
5.
What happens to air that is trapped in the bottle when you blow into the balloon?
______________________________________________________________________________________________________________________
______________________________________________________________________________________________________
6.
Design a modification to the balloon-in-a-bottle that will allow the balloon to inflate. Explain why your design works.
______________________________________________________________________________________________________________________
______________________________________________________________________________________________________
Mini Vocabulary Review: Draw lines matching the words to their definitions.

volume

a measure of the average kinetic energy of the particles in an object.

kinetic energy

a measure of the size of an object in three dimensional space.

pressure

the energy of an object that is due to the object’s motion.

temperature

the amount of force exerted per unit area on a surface.
The Kinetic-Molecular Theory of Gases
 The Kinetic Molecular Theory is a way to explain the properties of gases by examining the ___________________________________ at the
microscopic level. Gases that obey the Kinetic Molecular Theory are called ____________________________.
The Kinetic-Molecular Theory is based on five rules:
1.
Gases consist of _______________________________(molecules or atoms).
2.
The particles are TINY compared to the __________________________. So, we do not
count the volume of the particles.
3.
The particles are in __________________________________. The particles collide with
the ___________ of the container. These collisions result in
___________________________.
4.
The gas particles do not __________________________each other. They move randomly.
5.
The average kinetic energy of the gas is ___________________ to the Kelvin temperature.
Draw the gas particles moving
in a container here:
Chemistry
Ms. Boon
Name: ______________
Period: ____ Date: ______
Let’s Use the Kinetic-Molecular Theory (KMT) to Explain Properties of Gases: Draw pictures and take notes in the boxes below.
Diffusion – Diffusion is the movement of particles from areas of
Pressure and Temperature
_____________________ to _______________________.
As temperature increases, pressure __________________.
Notes from demonstration:
As temperature decreases, pressure _________________.
Notes from video:
Explain diffusion using the KMT:
Explain using KMT:
Pressure and Volume
Pressure and Number of Molecules
As volume increases, pressure _________________.
As the number of molecules increases, pressure __________.
As volume decreases, pressure ________________.
As the number of molecules decreases, pressure __________.
Notes from video:
Notes from video:
Explain using KMT:
Explain using KMT:
Practice: (1) Fill in the blanks with the term increase or decrease. (2) Explain your answer using the KMT. (3) Draw a before and after picture of
the gas particles in the box to the right.
1. Richard bought a new soccer ball and it came deflated. As he pumps air molecules into the
soccer ball, the pressure inside the soccer ball _____________. Why?
________________________________________________________________________
2. Leslie heated a sealed container with a fixed volume of 4 L over a fire. As the temperature of the
molecules inside the container increased, the pressure in the container ___________________.
Why? __________________________________
_______________________________________________________________________
3. Jonathan rode his bicycle over a nail, putting a hole in the tire which allowed gas molecules to
escape. This caused the pressure inside the tire to _________________. Why?
_______________________________________________________________
________________________________________________________________________
4. Sabrina brought a blown up balloon home from school. She put it in the freezer. As the
temperature of the air in the balloon decreases, the pressure of air in the balloon
__________________. Why? ___________________________________________
____________________________________________________________________
5. Sofia and Natalia climbed Mt. Everest. As they climbed up the mountain, the number of air
molecules around them decreased. This caused the air pressure to ____________. Why?
_____________________________________________________________________________________________________
Chemistry
Ms. Boon
Name: ______________
Period: ____ Date: ______
6. The cylinders in a car engine contain pistons that move up and down in order to increase and
decrease the volume of the cylinders. The cylinders are filled with a fixed amount of gas.
When the piston moves down, decreasing the volume of the cylinder, the pressure inside the
cylinder __________________. Why? ___________________
_____________________________________________________________________
7. In the car engine, when the piston moves up, increasing the volume of the cylinder, the
pressure inside the cylinder _____________. Why? __________________________
____________________________________________________________________
8. Someone farted in Chemistry class. As the smell spreads throughout the room, the number of
natural gas particles around whoever farted ______________. Why?
___________________________________________________________________
Multiple Choice Practice: Circle the best answer.
9. The atmosphere contains many different gases, such as
oxygen, carbon dioxide, and nitrogen. Which statement
explains why these gases diffuse into each other?
a)
b)
c)
d)
Gases have unreactive molecules
Gas molecules are close together
Gases have different-sized molecules
Gas molecules move in random motion
10. When someone standing at one end of a large room opens a
bottle of vinegar, it may take several minutes for a person at
the other end of the room to smell it. Gas molecules at room
temperature move at very high velocities, so what is
responsibvel for the delay in detection of the vinegar?
12. A sealed, empty plastic soda bottle containing only air was
transported from a mountain at an 8250-foot elevation to a
city at sea level. The reason why the walls of the soda bottle
caved inward at the lower elevation is the
a) sides of the bottle allowed more outside air to diffuse inward
b) concentration of air outside the bottle increased
c) molecule volume of O2 and N2 comprising air decreased
d) warmer air temperature caused air molecules to move slower
13. According to kinetic molecular theory, which picture shows
the correct movement of molecules in the balloon?
(a) the increase in the airspace occupied by vinegar
molecules
(b) the chemical reaction with nerves, which is slower than
other sensory processes
(c) attractive forces between the air and vinegar molecules
(d) random collisions between the air and vinegar molecules
11. The pressure exerted by a gas on a container is caused by
the
a) mass of the gas resting against the container.
b) gas particles hitting the walls of the container.
c) heat flowing from the gas particles into the container.
d) potential energy of the gas particles.
Activity: Make a poster illustrating one of the practice problems above. Or, make up your own scenario to illustrate. On the poster, describe the
scenario, explain whether pressure increases or decreases, and explain why using KMT. Finally, draw a before and after picture.
Challenge Question: A sample of gas occupies 524 mL at a pressure of 1.0 atm. The pressure is increased to 2.0 atm and the temperature is kept
constant. The volume decreases to 262 mL. Describe the numeric relationship between the change in pressure and change in volume. Write an
algebraic equation to illustrate this relationship.
Chemistry
Ms. Boon
Name: ______________
Period: ____ Date: ______
Exit Slip Standards 4a and 4b
4a: (1) Aerosol cans have a warning not to dispose of them in fires. Why? (use KMT)
(2) As the kinetic energy of molecules increases, the temperature __________. Why?
4b: (3) Why does methane gas (or any gas added to air) diffuse through air? Explain using KMT.
(4) How are molecules of different chemicals arranged when diffusion is complete?
Chemistry
Ms. Boon
Name: ______________
Period: ____ Date: ______
Exit Slip Standards 4a and 4b
4a: (1) Aerosol cans have a warning not to dispose of them in fires. Why? (use KMT)
(2) As the kinetic energy of molecules increases, the temperature __________. Why?
4b: (3) Why does methane gas (or any gas added to air) diffuse through air? Explain using KMT.
(4) How are molecules of different chemicals arranged when diffusion is complete?
Chemistry
Ms. Boon
Name: ______________
Period: ____ Date: ______
Exit Slip Standards 4a and 4b
4a: (1) Aerosol cans have a warning not to dispose of them in fires. Why? (use KMT)
(2) As the kinetic energy of molecules increases, the temperature __________. Why?
4b: (3) Why does methane gas (or any gas added to air) diffuse through air? Explain using KMT.
(4) How are molecules of different chemicals arranged when diffusion is complete?
Chemistry
Ms. Boon
Name: ______________
Period: ____ Date: ______