Student Exploration: Boyle’s Law and Charles’s Law
Vocabulary: absolute zero, Boyle’s law, Charles’s law, Gay-Lussac’s law, Kelvin scale, pressu... [Show More] re
Prior Knowledge Question (Do this BEFORE using the Gizmo.)
A small helium tank measures about two feet (60 cm) high. Yet it can fill over 50 balloons! How
can such a small tank contain enough helium to fill so many balloons?
The small container can hold all that helium in the container because the gas in the tank is
under a lot of pressure
The Boyle’s Law and Charles’s Law Gizmo shows a container
of gas. Inside, small purple spheres represent gas molecules.
1. Observe the particles. Are they all moving at the same
speed? Yes they are all moving at the same speed.
2. How do the particles interact with the walls and lid of the container?
The bounce off the walls and lid while providing pressure
These interactions contribute to the pressure on the walls of the container. Pressure is
defined as force per unit area. The SI units of pressure are newtons per square meter
(N/m2), or pascals (Pa).
3. Slowly drag the temperature (T) slider back and forth. (Note: In this Gizmo, the Kelvin scale
is used to measure temperature. On the Kelvin scale, 0 degrees is absolute zero, the
coldest possible temperature. Absolute zero is equal to -273.15 °C or -459.67 °F)
A. How does the change in temperature affect the speed of the molecules? Lower the
temperature slower the molecules. Higher the temperature the faster the molcecules.
B. How does the change in temperature affect the volume of the container? As the
temperature gets higher the pressure increases and the lid goes higher due to the
force being applied.2018
Get the Gizmo ready:
Set the temperature (T) to 300 K.
Check that the mass (m) is set to 0 kg.
Question: How does pressure affect the volume of a gas?
1. Form hypothesis: In this experiment, you will pile weights on the lid of the container of gas.
What do you think will happen as more weight is added to the lid?
The harder it will be for the pressure to keep it up.
2. Notice: Look at the DESCRIPTION pane. What is the mass of the lid? 10 kg
How much pressure does the lid exert on the gas? 98.1 N/m2
3. Collect data: With the temperature held constant at 300 K, use the Select mass slider to
place weights on the lid. Record the pressure and volume of the gas for each added mass [Show Less]