Boyle’s Law and Charles’ Law
Kyle Baseden
Chemistry I
Boyle’s and Charles’ Law
2/22
CCSS.MATH.CONTENT.HSA.SSE.A.1.A-Interpret parts of an expression, such as terms, factors, and
coefficients.
1. Materials
 1 250 mL flask
 water
 empty soda cans
 Bunsen burner
 Flint striker
 Glass dish
 ice
 tongs
 tube for Bunsen burner
2. Objective(s)
 Calculate the change in either the volume or pressure of a gas, when the amount and
temperature of a gas are kept constant.
 Calculate the change in either the volume or temperature of a gas, when the amount and
pressure of a gas are kept constant.
 Distinguish between the two gas laws.
 Use the correct law to solve the problem.
 Be able to apply pressure conversions taught previously to solve problems involving
pressure at different units.
3. Motivation
 If extra review is necessary, stations can be employed
o Students can work in their lab groups and move around the room solving
problems over pressure conversions.
o It can be determined whether this review is necessary based on the evaluations
done by the instructor informally in the previous lesson.
 Engagement
o Can crusher
 At the beginning of the lesson, students will see a can being heated up
with a small amount of water inside the can. The can will then be crushed
by atmospheric pressure.
 To crush the can
o Obtain an empty soda can, preferably a diet can
 Diet cans work better because the cans are made
with thinner walls.
o Fill the soda can with a small amount (about 10-15 mL of
water)
o Using tongs hold the can with water over a lit Bunsen
burner and heat until steam is released from the can.
o Upon boiling the water in the can,
Revised 4/11


The can should be removed from the flame and
immediately inverted into a dish containing ice
water.
 The can should be immediately crushed by
the pressure of the air around the can.
The instructor should ask the students if they have any idea how this could
happen using any knowledge they have.
 The reason this happens is that the volume of the gas decreases as
the temperature of the water vapor decreases. This reduces the
pressure the gas enacts on the interior of the can.
o As the pressure of the gas decreases inside the can, the
pressure outside the can due to the pressure from the air
remains constant.
 The pressure outside the can will be much higher
than the pressure inside the can causing the can to
become crushed under the pressure of the
atmosphere.
4. Goal for Learner
 Students should be able to use Boyle’s law or Charles’ law successfully to solve for a
change in either the pressure, volume or temperature of a gas.
 Students should be able to distinguish between Boyle’s and Charles’ law
 Students should be able to determine which law to utilize in order to solve any problems
given on the worksheet or future assessments.
5. Content and Procedures
 Boyle’s Law
o Robert Boyle used a J shaped tube which was closed on one side to determine the
relationship between the pressure and volume of a gas.
 He filled the tube with a certain amount of mercury and noted the volume.
He then added more mercury to the tube and noticed that the volume of
the gas decreased as more mercury was added.
 He then multiplied the pressure and volume observations and noticed that
the product of these values remained constant.
 This observation only holds true at a constant temperature and moles of
gas.
o If we remember that gas molecules must be in constant motion and constantly
colliding with the container’s surface…
 we can visually see how the pressure of the gas must increase as the
volume decreases.
 Because the volume of the gas decreases as the pressure increases, or
 The volume of the gas increases as the pressure decreases
 We say that the pressure and the volume of a gas are inversely
proportional to one another.
 We can mathematically represent Boyle’s Law with the equation
P1V1=P2V2
 Boyle’s Law practice
o Example
 A sample of neon to be used in a sign has a volume of 1.51 L under a
pressure of 635 torr. Calculate the pressure of the neon gas when it is
pumped into the tubes of the sign at a pressure of 785 torr.
Revised 4/11
o Example
 If the pressure of 2.4 L of gas in a balloon is 1.35 atm, what is the pressure
if the volume is increased to 5.4 L?
 Charles’ Law
o Jacques Charles
 1st person to fill a balloon with hydrogen gas
 1st person to make a solo hot air balloon voyage
 Studied the relationship between volume and temperature
 Determined that the volume of the gas increases as the temperature
of the gas is raised.
o This means there is a direct correlation between the volume
and temperature of a gas.
o IMPORTANT- you need all temperatures, when dealing
with gases, to be in Kelvin.
o Absolute zero
 From the data collected by Charles, it can be extrapolated what the
temperature would be of a gas when the volume is decreased to zero.
 We have to extrapolate because all gases liquefy before reaching this
lowest possible temperature.
 This temperature is called Absolute Zero.
 This is the lowest possible temperature possible
 Is a theoretical value; has not been reached but have gotten close
 Is the temperature in which there is no molecular motion.
 Temperature is the average kinetic energy of the particles.
o Volume and Temperature
 Charles found that the volume of a gas decreased when the temperature of
the gas was decreased. He also noted that the volume would increase
upon increasing the temperature.
 This is called a direct correlation.
 Both factors increase or decrease together.
 Charles’ Law is summarized in the equation
 Practice with Charles’ Law
o Example
 If the volume of a gas at 25 °C is 13.6 L, what is the volume of the same
gas at 35 °C?
 If the volume of a gas is 22.4 L at 25°C, what is the temperature when the
volume is 12.2L?
6. Practice/Application
 Students are to complete the worksheet over Boyle’s law and Charles’ law to help
students gain familiarity with the equations to be used throughout the chapter.
 The worksheet will be given to students after the lesson has been taught.
 Students are to work on the worksheet for the remainder of the class period, if time
permits.
7. Evaluation of student learning
 The instructor should make use of both formal and inform evaluations of student
performance to judge if any accommodations or alterations to future lesson plans need to
be made.
o Formal
Revised 4/11

The worksheet that students complete at the completion of the lesson
should be collected and graded for correctness.
 Based on student performance, any adjustments to future lessons,
such as the addition of a review activity at the beginning of
subsequent lessons may be deemed necessary.
o Informal
 During the lecture portion of the lesson, the instructor should make sure to
include many probing questions to assess that students are following along
with the material and understanding the concepts being discussed
throughout the lesson.
8. Closure
 Before letting students begin to work on the worksheet over Boyle’s and Charles’ Laws,
the instructor should make sure to tell students how the demonstration at the beginning of
the lesson was achieved.
o The instructor should have students try to provide an explanation of the
demonstration before giving the correct answer.
 The reason this happens is because as the temperature of the gas
decreases the volume the gas occupies decreases, so the pressure
from the atmosphere pushes on the balloon forcing it into the flask.
Revised 4/11