2. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
Introduction Part 1 - Boyle’s Law
Demonstration: Teachers may introduce this lesson by having students
attempting to compress the sides of empty 600ml plastic water bottles with a
tightly fitting cap. He/She will ask the students to describe what they feel. If the
students do not realize that the gases (air) inside the bottle push back, they will be
prompted to use the word "pressure" to describe the pushing back that they feel
on bottle.
Possible Answers:
1.No.
2.The volume
decreases.
3.Yes, temperature.
Questions:
1. Is there a change in the number of
particles or in the mass of the particles?
2. What happens to the volume of gas in
the empty bottles as you compress the
sides of the empty 600ml plastic water
bottle?
3. Is there any other variable which could
cause the empty 600ml plastic water
bottle and its contents to change? CHECK
3. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
Introduction Part 2- Charles’ Law
Teacher Demonstration
The teacher will show the students two inflated balloons of similar size and then,
he or she will place one in warm water and the other in ice. After a minute the
teacher will remove both balloons and then he or she will pass them around the
class.
Questions:
1.What happens to the volume of the balloon when it is warmed?
2.What happens to the volume of the balloon when it is cooled?
3.What variable was changed?
Expected Answers:
1.It expanded (increased).
2.It shrunk (decreased).
3.The volume and temperature of air
(gas) in the balloon.CHECK
4. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
Introduction Part 2- Charles’ Law
Questions cont’d
4.A boy bought helium balloons for his friend’s birthday in a warm store in Santa Cruz. He
noticed that the balloons shrunk and they weren’t floating as high when he took them to a
very cold air conditioned room. Why was this happening?
5.What is the relationship between gas volume and temperature?
Expected Answers:
4.The temperature of the room caused
the temperature in the balloons to
decrease. This causes a decrease in the
volume of the balloons, hence a decrease
in the upthrust.
5.As the temperature increases, the
volume of gas will increase.CHECK
5. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
Introduction Part 3 - Pressure and General
Laws
Teacher Demonstration: The teacher places a glass bottle of diameter
approximately 4 cm in front of the students. Then he or she will put four lit match
sticks inside the bottle. This will be followed by the teacher placing a peeled
hardboiled egg over the mouth of the bottle.
Question 1: What happens to the egg when the match sticks went out? Give reasons for
your answer?
Expected Answer to Question 1
The egg will be sucked into the bottle. This is due to the drop in pressure as the air
inside cooled from the match sticks going out (slower colliding air molecules with
inside walls of bottle). The air pressure outside remains the same thus pushing the egg
into the bottle CHECK
6. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
Introduction Part 3 - Pressure and General
Laws
Teacher Demonstration: The teacher places a glass bottle of diameter
approximately 4 cm in front of the students. Then he or she will put four lit match
sticks inside the bottle. This will be followed by the teacher placing a peeled
hardboiled egg over the mouth of the bottle.
Question 2: How would you get the egg out of the bottle?
Expected Answer to Question 2
This can be done by inverting the bottle so that the egg is covering the opening. Then you
will run hot water over the bottle. Another way that you could get the egg out of the
bottle is by placing your mouth over the opening inverted bottle and blow hard across the
mouth of the bottle. CHECK
7. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
Objectives
As a result of this lesson, the student will be able to:
1.conduct an experiment to verify Boyle’s Law
2.deduce the formula PV= k from an experiment
3.use the formula PV= k in calculations in problems based on Boyle’s Law.
4.conduct an experiments to verify Charles’ gas law
5.deduce the formula from an experiment
6.use the formula in calculations in problems based on Charles’ gas law.
7.discuss how knowledge of combined gas law does what?
8.conduct an experiments to verify the Pressure law
9.recall mathematical expressions describing the Pressure Law and the Combined
Gas Law.
10.use the mathematical formula for the pressure and combined gas laws to
solve problems
8. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
1 - Boyle’s Law
Look at the animated clip on the right and then answer the questions.
1.What are the constant variables ?
2.What are changing variables?
3.What is the relationship between the changing variables?
Taken from http://crsic.umbb.dz/gaslaws.ppt
Answer to Qu. 3:
Pressure is inversely proportional to volume.
Answer to Qu. 1: Temperature and mass.
Answer to Qu. 2: Pressure & Volume CHECK
10. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
1 - Boyle’s Law (cont.)
Graphs of Boyle’s Law:
pressure
volume
volume
1
pressure
Application of Boyle’s Law
A bicycle pump is a good example of Boyle’s law.
As the volume of the air trapped in the pump is reduced,
its pressure goes up, and air is forced into the tire.
11. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
1 - Boyle’s Law (cont.)
Example 1.1
A sample of gas has a volume of 30 cm3
at a pressure of 2x105
Pa.
Calculate the new volume of gas when the pressure is increased to 4x105
Pa,
assuming the temperature remains constant.
Pa102P 5
1 ×=
3
1 cm30V =
5
2P 4 10 Pa= ×
?V2 =
2211 VPVP =
( ) ( )5 5
22 10 30 4 10 V× × = × ×
( )6 5
26 10 4 10 V× = × ×
6
2 5
6 10
V
4 10
×
=
×
3
2V 15 cm=
SHOW ME.
12. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
1 - Boyle’s Law - Activity
In groups of four, the teacher will ask the students to discuss how
Boyle’s law governs the following Phenomena.
1. The use of syringes used in medicine.
2. The use of spray cans in spraying paint and air freshener.
3. Inhalation and exhalation in respiration.
4. The combustion of fuel in the pistons of a vehicle.
5. The blowing of bubbles and causing them to pop.
After approximately five minutes in their discussion the students will
be asked to halt their group discussion and will be engaged in a brief
class discussion.
13. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
2 - Charles’ Law
1. What are the constant variables ?
2. What are the changing variables ?
3. What is the relationship between
the changing variables?
Taken from http://crsic.umbb.dz/gaslaws.ppt
Answer to Qu. 1: Pressure and mass.
Answers to Qu 2: Temperature & Volume
Answer to Qu. 3: Volume is directly
proportional to the absolute temperature.CHECK
14. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
2 - Charles’ Law (cont.)
What is Charles’ Law?
Charles’ Law states that the volume of a constant mass of gas is directly
proportional to the absolute temperature if the pressure remains constant.
2
2
1
1
T
V
T
V
=
constant
T
V
=TV∝
This is used in the form:
volume
(m3
)
temperature
(K)
When using this equation you must use temperature as kelvin (K).
15. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
2 - Charles’ Law (cont.)
Graphs of Charles’ Law
o
V
T / C
-273
When the graph is extended back ( the dotted line) until the volume
reaches zero, it crosses the axis at -273°C.
If the graph is volume against temperature in kelvin, the graph will show
volume to be directly proportional to temperature as shown below.
V
T / K
0
NOT directly
proportional
directly proportional
16. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
2 - Charles’ Law (cont.)
Example 2.1
60 cm3
of a gas is at 27 °C. Calculate the volume of this gas at 10 °C, if the
pressure is unchanged.
3
1V 60 cm=
C27T1 °=
?V2 =
2
2
1
1
T
V
T
V
=
27327 +=
K300=
C10T2 °=
27310 +=
K283=
260 V
300 283
=
2300 V 283 60× = ×
2
16,980
V
300
=
3
2V 56.6 cm=
What would the volume
be if you did not
convert to Kelvin?
22.2cm3
WRONG
SHOW ME.
18. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
3 - Pressure Law (cont.)
What is Pressure Law?
Pressure Law states that the pressure of a constant mass of gas is directly
proportional to the absolute temperature if the volume remains constant.
2
2
1
1
T
P
T
P
=
constant
T
P
=TP ∝
This is used in the form:
pressure
(Pa – Pascal)
temperature
(K)
When using this equation you must use temperature as kelvin
(K).
19. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
3 - Pressure Law (cont.)
Graphs of Pressure Law
The straight line graph does
not pass through the origin.
p
T / oC
-273
If the graph is extended back until the pressure reaches zero, it will cross the axis
at -273°C. This is known as absolute zero.
If the pressure against temperature in kelvin graph is drawn, the graph will show
pressure being directly proportional to temperature.
p
T / K0
NOT directly
proportional
directly
proportional
20. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
3 - Pressure Law (cont.)
Example 3.1
A quantity of gas has a pressure of 2.5x104
Pa at a temperature of 20 °C.
Calculate the new pressure when the temperature reaches 37 °C assuming the
volume remains constant. To see solution, click
4
1P 2.5 10 Pa= ×
C20T1 °=
?P2 =
2
2
1
1
T
P
T
P
=
27320 +=
K293=
C37T2 °=
27337 +=
K310=
4
22.5 10 P
293 310
×
=
( )4
2293 P 310 2.5 10× = × ×
5
2
77.5 10
P
293
×
=
4
2P 2.65 10 Pa= ×
SHOW ME.
21. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
4 - Combined Gas Law
What is the Combined Gas Law?
Combined Gas Law states that the ratio of the product of pressure and volume to
the absolute temperature, is a constant.
constant
T
VP
=
×
2
22
1
11
T
VP
T
VP
=pressure
(Pa)
When using this equation you must use temperature as kelvin (K).
This equation is used in the form:
temperature
(K)
volume
(m3
)
23. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
4 - Combined Gas Law (cont.)
Example 4.1 A sample of nitrogen gas has a volume of 0.180 L, at a pressure of
0.800 atm and a temperature of 29°C. What is the new temperature(°C) of the
gas at a volume of 90.0 mL and a pressure of 3.20 atm?
Solution
P1 = 0.800 atm V1 = 180 mL T1 = 302 K
P2 = 3.20 atm V2= 90 mL T2 = ??
2
22
1
11
T
VP
T
VP
=
2
0.8atm 180 3.2atm 90
302K T
ml ml× ×
=
2
288
0.477
T
= 2
288
T 603.8 604
0.477
= = ≈
0
2T 604 273 331 C= − =
31. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
Quiz: Question 4
Calcium Carbonate usually decomposes at 1200 0
C to form carbon
dioxide and calcium oxide. 45 liters of carbon dioxide are collected
at 1200 0
C. If it is allowed to cool, what will be the volume of this gas
at 25 0
C, assuming the pressure remains constant?
31
A. 2160ml
D. 67ml
C. 0.93ml
B. 9.1ml
FEEDBACKFEEDBACK
32. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
Quiz: Feedback to Question 4
Calcium Carbonate usually decomposes at 1200 0
C to form carbon
dioxide and calcium oxide. 45 liters of carbon dioxide are collected
at 1200 0
C. If it is allowed to cool, what will be the volume of this gas
at 25 0
C, assuming the pressure remains constant?
32NEXT QUESTIONNEXT QUESTION
1 2
1 2
2
2
V
45
1473 298
13410
9.1
1473
V
T T
L V
K K
LK
V L
K
=
=
= =
35. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
QUIZ: Question 6
In your notebook, do the following questions. Click CHECK for answers.
a.A balloon contains 30.0 L of He gas at 103kPa. What is the volume of He when
the balloon rises to an altitude where the pressure is only 25.0kPa, assuming the
temperature remains constant?
b.A balloon inflated in a room at 24.0˚C has a volume of 4.00 L. The balloon is
heated to a temperature of 58.0˚C. What is the new volume, assuming the
pressure remains constant?
c.A sample of N2(g) is at STP. What will the pressure (in atm) be if the temp is
increased to 373K at constant volume?
d.The volume of a gas-filled balloon is 30.0L at 98.0˚C and 1147 mmHg. What
would the volume be at STP?
END OF QUIZEND OF QUIZ
Answers: a) 156 L b) 4.46 L c) 1.37 atm d) 33.3 LCHECK
37. OBJECTIVES
BOYLE’S
LAW
CHARLES’
LAW
PRESSURE
LAW
COMBINED
GAS LAW
QUIZINTRODUCTION
X
References
Charles Law PowerPoint - Temperature & Volume Relationship. Retrieved from
http://www.chalkbored.com/lessons/chemistry-11/charles-law.ppt on Friday,
July27,2012.
Gases Retrieved from
http://www.chemistrygeek.com/chemistrypowerpoint/Student%20Ch
%2013%20Gases.ppt on Friday ,July27,2012.
Gas Laws Retrieved from http://www.google.com.jm/url?sa=t&rct=j&q=real
%20life%20application%20of%20combined%20gas%20law%20in
%20doc.&source=web&cd=20&ved=0CGoQFjAJOAo&url=http://staffweb.psdscho
ols.org/rjensen/powerpoints/gas_laws_pp_lauren1.ppt&ei=eCIbUP3SDuXk0QGSIC
QCg&usg=AFQjCNEoohP4BrJbAQwPReV6EpNnbLxSwg&sig2=338kld6X3LP5vS6rJJZ
nyA on Friday, July27, 2012.
