Modeling Pressure Volume and
Temperature of Gases
Summary Table Review
Combining Liquids
Diffusion of Particles
• In this demo, we dropped food coloring into glasses
of hot water and cold water.
• We observed that the dye spread out in the water
and eventually was evenly spaced in the entire
volume of water (aka “diffusion”)
• We noticed that the rate of diffusion corresponded
with the temperature of water.
Candle in Jar
• In this lab, we measured the mass of the system
before the candle was lit and after the candle
burned out.
• We observed that the mass of the closed system
didn’t change.
• We can explain these observation using our
understanding that in a closed system, mass is
conserved, because no particles can leave the
system.
Sand, Water, & Air
• In this lab, we measured the mass and
volume of the system before and after
compressing the plunger
• We observed that the solid and liquid
materials did not compress, while the
gas did compress.
• Particles in liquids and solids are always
in contact with the surrounding particles,
there is no space between particles in
liquids and solids and there is space
between particles in gases.
Imploding Tanker
• In this video, we observed a tanker filled with hot
steam implode after sitting outside on a cold day.
• We considered many ways of explaining these
observations using what we know about particles and
their motion.
• By the end of this unit, we used evidence to decide on
the best particle model. Discuss:
– Which particle models were ruled out and why?
– Which particle model did we keep and why?
Build a Thermometer
• In this lab, we heated up water in flasks
a test tube that had glass pipettes
attached through the stopper.
• We observed that the level of the liquid
increased as the temperature of the
water increased.
• We explained our observations through
our understanding of temperature as a
measurement of the average kinetic
energy of particles.
Pressure and Volume Lab
• In this lab, we put a marshmallow in a syringe and changed
the volume inside of the syringe by pulling or pushing on
the plunger.
• At each volume, we measured the pressure using the mini
computers.
• We observed that as the volume increased the pressure
decreased.
• We explained our observations through our understanding
that when the same number of particles are in a smaller
space, they hit the sides of the container more frequently,
which results in a pressure increase.
Pressure and Temperature Lab
• In this lab, we heated up air in a
flask by immersing it in a water bath.
• We measured how the pressure of
the gas changed as we increased the
temperature of the water bath.
• We observed that the longer we left the flask of air
in the hot water, the higher the pressure became.
• We explained our observations through our
understanding of temperature as a measurement of
the average kinetic energy of particles in a closed
container.
PVT PhET Simulation
• In this computer model, we pumped gas
particles into a box.
• We observed that:
– Adding heat increased the pressure in the box.
– Decreasing the size of the box increased the pressure in the box.
– Adding more particles increased the pressure of the box
• We explained our observations through our understanding
that:
– When the average temperature of particles is increased, particles hit
the sides of the container they are in more frequently, which results in
a pressure increase.
– When particles are in a smaller space, they hit the sides of the
container more frequently, , which results in a pressure increase.
– When the number of particles in a closed container is increased, there
are more particles hitting the sides of a container, which results in a
pressure increase.