introduction to charles's law

2. Discussing new concepts and practicing new skills #1
Let us show the relationship between volume of a gas and temperature by
doing the activity below.
Do Activity 2.2 entitled: “GRAPHING CHARLES’ LAW”
Materials needed: graphing paper, ruler, pencil, and calculator
Given:
A gas cylinder was measured to have different volumes at different
temperatures as shown in the table below.

3. 2.) Plot the data from table 1 in a graph by placing the volume (ml)
in the y-axis and temperature (Kelvin) in the x-axis.
Guide Questions:
1.) Describe the shape of the graph.
2.) How is this graph different from the graph you obtained in
Boyle’s law?
3.) Based on the graph, what relationship exist between the
volume of a gas and temperature?
4.) What are the constant variables in Charles’ law?
5.) State Charles’ law based on your answer of question 3 and
question 4. (EXPLAIN)
Procedure:
1.) Complete the missing data on the last column using the
formula K = oC + 273.

4. 275
330
375
425

5. 275, 25
330, 30
375, 35
425, 40
0
20
40
60
0 100 200 300 400 500
VOLUME
IN
ML
TEMPERATURE IN KELVIN

6. Guide Questions:
1.) Describe the shape of the graph.
2.) How is this graph different from the graph
you obtained in Boyle’s law?
3.) Based on the graph, what relationship exist
between the volume of a gas and temperature?
4.) What are the constant variables in Charles’
law?
5.) State Charles’ law based on your answer of
question 3 and question 4.

7. Jacques Charles
The volume – temperature
relationship in gases (k = V/T) was
determined by and named after
Jacques Charles.

10. Let us derive the formula of Charles’ law.
Mathematically, Charles’ Law can be expressed as:
V α T at constant P
Where:
V = volume and
T = temperature expressed in Kelvin

11. Since volume and temperature are directly proportional, if we equate
initial condition (before) and final condition (after)
V1= V2
T1 T2
Just cross multiply initial condition and final
condition to get the final formula, it will become,
V1T2 =V2 T2
Whereas,
V1 is the initial volume and V2 is the final volume
T1 is the initial temperature and T2 is the final
temperature

12. Let us apply the derive formula in a sample problem. Solve (Show your
solution in GUFSA form)
1. A tank (not rigid) contains 2.3 Liters of
helium gas at 25 oC. What will be the
volume of the tank after heating it and its
content to 40 oC temperature at constant
pressure?

13. Solve (Show your solution in GUFSA form)
At 20.0 oC, the volume of chlorine gas is
15.0 cm3. Compute the resulting volume if
the temperature is adjusted to 318.0 K
provided that the pressure remains the
same.

14. Under constant pressure
condition, a sample of hydrogen
gas initially at 85oC and 7.2 L is
cooled until its final volume is 4.1
L. What is final temperature?

16. The following are only a few of the applications of Charles’ law
in our life.
Bread dough rises
The bursting of car tires increases during summer
Sky lanterns have the same concept with hot air balloons
When you put the dented ping pong ball in hot water
When inflated pool floats are pushed into pools, they
appear as under inflated.

17. Making generalizations and abstractions about the lesson
After learning about Charles Law, let us summarize the lesson as follows:
● Charles’ Law states that at constant pressure, the volume of a fixed
amount of gas is directly proportional to the Kelvin (K) temperature.
● This means that as temperature increases, the volume of a gas increases,
and as the temperature decreases the volume of a gas decreases.
● Kelvin (K) is the basic unit for measuring temperature using the equation
K = oC+ 273.15
● Pressure and amount of gas are the constant variables in Charles’ law.
● The general formula for Charles’ law is V1T2 = V2T1
● The proponent of Charles’ law is Jacques-Alexandre-César Charles or
commonly known as Jacques Charles.
● The graph that shows straight line is a direct proportionality
relationship.