Rosalio Eduarte National High School Dolores, Abra Detailed Lesson Plan in Science 10 I. Objectives At the end of the lesson, the students are expected to: a. explain the effect of changes in volume and temperature; b. use the volume-temperature relationship to determine the new volume or temperature of a given amount of gas at a constant pressure; and c. give practical applications of Charles’s law. II. Subject Matter Charles’s Law
Topic:
Materials: PowerPoint presentation, Video clips related to Charles’s law, balloons, hot water, ice, beaker, ice, pail References: Fundamentals of Chemistry, 5th Edition by Goldberg, D. ; Conceptual and Functional Chemistry – Modular Approach, 2nd Edition by Padolina, M., et.al and Exploring Life through Science, Chemistry Laboratory Manual by Bayquen, Science 10 learner’ and teacher’s materials III. Procedure Teacher’s Activity A. Preliminary activities a) Prayer May we all stand and let us pray. Let’s bow our head and feel presence of God. (Amen!) b) Customary Greetings “Good morning Class!”
Learner’s Activity
the
How are you today?
(Amen!) “Good morning, sir!” We’re good sir!
Have you taken your breakfast? That’s good! Everyone! Before taking your seats, kindly arrange your chairs and pick up all the litters.
Yes sir
You may now take your seats. Thank you, sir! a) Checking of attendance Who are absent today? Are you all present?
Yes sir!
That’s good! B. Review of the Past Lesson What was our topic last meeting? Anyone? Yes Apple?
We talked about behavior of gases sir!
Very good! What else? Yes Aerwin? Sir!
Very good!
We also learned about Boyle’s law which states that if volume decreases the pressure increases. And we are also done for the activity about the second law of gases which is the Charles’ Law.
B. Motivation Let’s watch a video related about your activity last meeting which is the Charles’ Law. C. Presentation That’s our activity all about! So, today let’s have a continuation of that topic which is Charles’ law. D. Discussion Through our activity last meeting we’ve learned that when the temperature of a gas increases, its volume increases and vice versa. This is the principle of Charles’ Law of Gases. Before we proceed for the calculations we need to know who is the man behind this law or who introduced this law? Do you have any idea?
Very Good! In Charles’ Law the Kelvin temperature of a gas is directly related to the volume where P (Pressure) and n (amount of air) are constant. •
For two conditions, Charles’ Law is
-
Sir! He is Jacques Alexandre César Charles, a French inventor, scientist, mathematician, and balloonist.
V T
written = V (P and n constant)
1
2
T
1
•
2
Rearranging Charles’ Law to solve for V 2
T xV 2
T V
2
= V x T
1
2
T
1
=
V xT 1
1
1
2
T
1
Let’s have an example applying the Charles’ Law equation; a. A balloon has a volume of 785 mL at 21°C. If the temperature drops to 0°C, what is the new volume of the balloon (P constant)? 1. Set up data table: Conditions 1
Conditions 2
V1 = 785 mL
V2 = ?
T1 = 21°C = 294 K 2. V T
1
1
V
2
Solve Charles’ law for V : 2
= V T
2
2
= V x T 1
2
T V
2
T2 = 0°C = 273 K
1
= 785 mL x 273 K = 729 mL
294 K Again, let’s have another problem to solve for you to understand well, for now you’re going to solve on your own. Seatwork; 5 minutes, ¼ sheet of paper a. A sample of oxygen gas has a volume of 420 mL at a temperature of 18°C. At what temperature (in °C) will the volume of the
oxygen be 640 mL (P and n constant)? (after five minutes) I want two volunteer, boy and girl show your computation in front and explain.
1. Set up data table: Conditions 1 V1 = 420 mL T1 = 291 K
Conditions 2 V2 = 640 T2 = ?
2. Solve Charles’ law for T2: T 2 = T 1 x V2 V1 T2
= 291 K x 640 mL = 443 K 420 mL = 443 K - 273 K = 170°C
Very good! E. Generalization So, that’s our entire topic for today! So let’s sum up! What is the principle of Charles’ Law?
When the temperature of a gas increases, its volume increases. The Kelvin temperature of a gas is directly related to the volume. P and n are constant.
Very Good! IV. Application Let’s have an activity ; a Quiz bee. I have here set of problems and questions, you’re going to answer it by group. For now let’s make your group into 4… Everyone stay with your group mates! So, here are the rules; for easy round I will give you 30 seconds for you to answer the questions, 1
point for correct answer, for difficult round I will give you 1 min. and 30 seconds to answer! 3 points for correct answer. Write your answers in the cardboard, if I tell you ‘time’s up!’ you’re going to raise your cardboard. Understood? Yes, sir! Easy round; 1. Who introduced Charles’ Law? Complete
Jacques Alexandre César Charles
name 2. What is the formula in computing T2 ? 3. What is the equation that you can derive on the principle of Charles’ Law? Difficult round; Solve the following problems 1. A cylinder with a movable piston contains 250 cm3 air at 10 degrees Celsius. If the pressure is kept constant, at what temperature would you expect the volume to be 150 cm3? 2. A tank (Not rigid) contains 2.3 L of Helium gas at 25 degrees Celsius. What will be the volume of the tank after heating it and its content to 40 degrees Celsius temperature at constant pressure? V. Evaluation ½ sheet of paper Use the gas laws to complete sentence with 1) increases
2) decreases.
A. Pressure _______, when V decreases. B. When T decreases, V _______.
T 2 = T 1 x V2 V1 V1 T1
= V2 T2
(P and n constant)
C. Pressure _______ when V changes from 12 L to 24 L D. Volume _______when T changes from 15 °C to 45°C Solve for the following; 1. At 20 degrees Celsius, the volume of Chlorine gas is 15 dm3. Compute for the resulting volume if the temperature is adjusted to 318K provided that the pressure remains the same. VI. Assignment Who is the man behind Gay-lusac’s Law? What is the principle of Gay-Lussac’s Law? Write it in ¼ sheet of paper.
Prepared by;
HAJI DARELL BAGTANG
Presented to;
Practice Teacher
MR. JUDY TACIS Critique Teacher
