BOYLE’S LAW
for SCIENCE Grade 10
Quarter 4/ Week 1
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FOREWORD
The Department of Education through the Bureau of
Curriculum Development Curriculum Standards Development
Division has crafted the Most Essential Learning Competencies
(MELCs) to address the needs and demands brought about by
the pandemic.
This Self-Learning Kit serves as an alternative learning
material that discusses the general properties of gases, the
scientific postulates as stated in the kinetic molecular theory,
and the relationship between volume and pressure at constant
temperature and amount of gas.
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OBJECTIVES
At the end of the lesson, you should be able to:
K: describe the scientific postulates of kinetic molecular theory
S: perform simple calculations applying principles of Boyle’s Law
A: recognize the importance of Boyle’s Law in real-life situation
LEARNING COMPETENCY
Investigate the relationship between volume and pressure
at constant temperature of gas and amount of gas. (S10MT-IVab-21)
I. WHAT HAPPENED
Pre-Assessment
Directions: Answer the following questions below about volume–
pressure relationship and write your answer in your
notebook.
1. Who is the Irish scientist who discovered the inverse relationship
between volume and pressure at constant amount of gas?
2. Which law states that the volume occupied by a gas is inversely
proportional to the pressure if the temperature and amount of
gas remains constant?
3. If a fixed amount of gas occupies 3.60 liters at a pressure of 1.00
atm at 25°C. What will be its volume at a pressure of 2.50 atm if the
temperature remains constant?
4. A gas occupies 1.56 L at 1.00 atm. What will be the volume of the
sameamount of gas if the pressure becomes 3.00 atm?
5. Give one application of Boyle’s Law.
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II. WHAT I NEED TO KNOW
Gas can be found around us. It is part of our daily living as there are tools
which we use that apply some principles governing gas properties.
Some of the principal general properties of gases may be listed below:
1. Gases are compressible.
2. Gases fill any container that they occupy.
3. Different gases mix completely.
4. Gases expand in the presence of heat.
5. Gases do not settle in their container.
According to the kinetic molecular theory (KMT), gases consist of tiny,
discrete molecules, each of which has a mass. In gases, these molecules are
relatively far apart with empty spaces between them. This is why gases can easily
be compressed.
Gas molecules are in constant, rapid, random motion. They move in straight
lines until they collide with other molecules, or with the walls of the container. This
movement explains the filling of containers by gases and the mixing of gases. The
moving gas molecules exert pressure in the container. A given pressure is the resultof
the number of such collisions in a unit of time. Gas pressure is increased by the
following:
1. Forcing more gas into the container, thereby increasing the number
of collisions per unit time
2. Decreasing the volume of gas, thus shortening the average
distance between the molecules and eventually increasing the
number of collisions per unit time
3. Heating the gas in a closed container, thereby increasing the speed of
the molecules and the number of collisions per unit time
The speed of the moving molecules is the result of the kinetic energy, and this
energy increases by heating the gas and decreases by cooling it. The KMT
suggests that the collision of the gas molecules with other molecules or with the
walls of the container are perfectly elastic. In effect, collisions take place without
loss of energy either through friction or through any other means.
Before we proceed in discussing the laws related to properties of gases, take
a look at this list below of the scientific postulates of the kinetic molecular theory.
1. A gas consists of very small particles, each of which has a mass.
2. The distances separating gas particles are relatively large.
3. Gas particles are in constant, rapid, and random motion.
4. Collisions of gas particles with each other or with the walls of the container
are perfectly elastic.
5. The average kinetic energy of gas particles depends only on the
temperature of the gas. Gases have higher kinetic energy at a higher
temperature and lower kinetic energy at a lower temperature.
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6. Gas particles exert a force on one another. In other words, the attractive
forces between gas particles are so weak that the model assumes them to
be zero.
Boyle’s Law: Pressure and Volume
Source: t.ly/5Z54
Air is all around us consisting of plenty of molecules moving rapidly in all
directions. We do not feel the pressure exerted on our body because we experience
the same pressure from the air molecules within our body. That is, the pressures are
equal.
The pressure of the gas is the force it exerts on the wall of its container. On the
other hand, volume is the amount of space that a substance or object occupies.
Let us try to determine the relationship of the two by looking at the graph
below.
BOYLE’S LAW
(temperature = constant)
Source https://tinyurl.com/3sw8xksh
The figure above shows a graph of pressure and volume. Kindly note that as
the pressure increases the volume of the gas decreases, and as the pressure
decreases the volume increases.
If there is a decrease in the volume of gas, air molecules will have less space
to move. Therefore, molecules will strike the walls of the container more often andwill
result to a greater pressure.
The relationship between the volume of a given quantity of a gas and its
pressure is expressed by Boyle’s Law. This law states that the volume occupied by a
gas is inversely proportional to the pressure if the temperature remains constant.
Meaning, at constant temperature, if there is an increase in pressure, volume will
decrease. If there is an increase in volume, pressure will also decrease. Boyle’s Law
is expressed using the equation:
P1V 1 = P2V 2
where:
P1 = initial pressure
V1 = initial volume
P2 = final (resulting) pressure
V2 = final (resulting)volume
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Robert Boyle, an Irish scientist,
discovered the inverse relationship
between volume and pressure.
Source: t.ly/AZUT
The table below shows units for measuring pressure and volume.
Units for Measuring Pressure
Symbol
Unit
Atmosphere
atm
mm Hg
torr
Pa
Millimeter of Mercury
Torricelli
Pascal
Units for Measuring Pressure
Unit
Units Equivalent to 1atm
1atm
760 mm Hg
760 torr
101 325 Pa (=105 Pa)
Atmosphere
Milliliter of Mercury
Torricelli
Pascal
Units for Liquid Measurement
Unit
Symbol
mL
cm3
L
Milliliter
Cubic centimeter
Liter
Since you already have an idea on how volume and pressure are related,
letus try to solve a problem involving these two.
Sample Problem
A. What volume will 500 mL of gas initially at 25° C and 750 mm Hg
occupywhen the condition changes to 650 mm Hg at the same
temperature?
Solution
Consider first that the temperature is constant. Therefore, we can use
Boyle’s Law. Note also that P1 is 750 mm Hg, V1 is 500 mL, and P2 is 650 mm Hg.
Initial
Final (Resulting)
P2 = 650 mm Hg
P1 = 750 mm of Hg
V2 = ?
V1 = 500 mL
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Then using,
P1V 1 = P2V 2
P2V 2 = P1V 1
P2V2
P1V1
=
P2
P2
V2 = P1V1
P2
Substituting the given values for initial and final pressure and volume as reflected inthe
table above.
V2 = 750 mm Hg x 500 ml
650 mm Hg
V2 = 576.92 ml
ACTIVITY
Directions: In your notebook, solve the problem below and show your solution.
What volume will 400 mL of argon gas initially at 30° C and 725 mm Hg
occupy when the condition changes to 650 mm Hg at the same temperature?
There are several applications of Boyle’s Law that greatly helped us
especially in the field of medicine.
One of the direct applications of Boyle’s Law is seen in a chest respirator. A
machine used in the treatment of patients with respiratory difficulties. When the
pressure inside the respirator is decreased, the air in the lungs expands, forcing the
diaphragm down. When the pressure of the respirator is increased, the volume of air
in the lungs is decreased, allowing the diaphragm to move upward again. This
alternate increase and decrease in pressure enable the patient to breathe even
though he or she cannot control the movement of the diaphragm muscles.
Another example of Boyle’s Law is in the use of a sphygmomanometer, a device used
to measure blood pressure. When the rubber bulb is squeezed, the volume of air in that
bulb is decreased and its pressure is increased. This increased pressure is transmitted to
the cuff.
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A picture that shows a patient with Covid-19 being treated with the use of chest respirator.
Source:
https://tinyurl.com/yckr9u5h
Source: Chemistry for the Health
Sciences, 8th Edition Georgie I.
Sackheim, Dennis D. Lehman
A sphygmomanometer, a device used to measure blood pressure.
III.WHAT I HAVE LEARNED
Directions: Write the letter of your choice in your notebook.
1. A gas occupies 12.3 liters at a pressure of 40.0 mmHg. What is the volume
when the pressure is increased to 60.0 mmHg at constant temperature?
a. 9.2 L
b. 8.2 L
c. 7.2 L
d. 10.2 L
2. Which of the following states that the volume occupied by a gas is inversely
proportional to the pressure if the temperature remains constant?
a. Charles’ Law
b. Boyle’s Law
c. Kinetic Molecular Theory
d. Avogadro’s Law
3. A gas occupies 1.56 L at 1.00 atm. What will be the volume of this gas if the
pressure becomes 3.00 atm?
a. 0.52 L
b. 0.53 L
c. 0.54 L
d. 0.55 L
4. A gas occupies 11.2 liters at 0.860 atm. What is the pressure if the volume
becomes 15.0 L?
a. 0.69 atm
b. 0.67 atm
c. 0.64 atm
d. 0.66 atm
5. The following are applications of Boyle's Law except
a. syringe
c. automobile engine
b. medical respirator
d. spray nets
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REFERENCES
Science 10 Learner’s Material. Department of Education, n.d.
Science 10 Teacher’s Guide. Department of Education, n.d.
Soriano, Emil F., et. al. (n.d.) Chemistry for the New Millennium.
Adriana Publishing Co., Inc.
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DEPARTMENT OF EDUCATION
SCHOOLS DIVISION OF NEGROS ORIENTAL
SENEN PRISCILLO P. PAULIN, CESO V
Schools Division Superintendent
JOELYZA M. ARCILLA EdD
OIC - Assistant Schools Division Superintendent
MARCELO K. PALISPIS EdD JD
OIC - Assistant Schools Division Superintendent
NILITA L. RAGAY EdD
OIC - Assistant Schools Division Superintendent/CID Chief
ROSELA R. ABIERA
Education Program Supervisor – (LRMDS)
ARNOLD R. JUNGCO
PSDS – Division Science Coordinator
MARICEL S. RASID
Librarian II (LRMDS)
ELMAR L. CABRERA
PDO II (LRMDS)
LEONREY L. VAILOCES
Writer
LEONREY L. VAILOCES
Illustrator/Lay-out Artist
ALPHA QA TEAM
ALLAN Z. ALBERTO
SEGUNDINO B. DELES, JR.
MANASSES V. JABALDE
VERONICA A. RECTO
BETA QA TEAM
ZENAIDA A. ACADEMIA
ALLAN Z. ALBERTO
EUFRATES G. ANSOK JR.
ROWENA R. DINOKOT
CHRISTINE A. GARSOLA
LESTER C. PABALINAS
DISCLAIMER
The information, activities and assessments used in this material are designed to provide accessible learning
modality to the teachers and learners of the Division of Negros Oriental. The contents of this module are carefully
researched, chosen, and evaluated to comply with the set learning competencies. The writers and evaluator were
clearly instructed to give credits to information and illustrations used to substantiate this material. All content is subject
to copyright and may not be reproduced in any form without expressed written consent from the division.
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Pre- Assessment
1. Robert Boyle
2. Boyle’s Law
3. 1.44L
4. 0.52L
5. Syringe, medical
respirator, etc.
This Self-Learning Kit aims to explain in a
simple manner the relationship of volume and
pressure.
Learners are expected to understand the
relationship between volume and pressure,
solve related problems, and recognize its
importance to our daily living.
Post Test
1. B
2. B
3. A
4. C
5. D
SYNOPSIS
ANSWER KEY
About the AUTHOR and LAY-OUT ARTIST
This module was written and designed by LEONREY L.
VAILOCES, a Secondary School Teacher teaching Science
at Demetrio L. Alviola National High School. He is a graduate of
Bachelor’s Degree in Secondary Education and has started
taking Master of Arts in Science Teaching at Negros Oriental
State University.
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