Physics - Senior Secondary 2 - Gas laws

TERM: 1^ST TERM

WEEK: 4

Class: Senior Secondary School 2
Age: 16 years
Duration: 40 minutes for each of 5 periods
Date:
Subject: Physics
Topic: Gas Laws
Subtopics:

• Measurement of gas pressure
• Barometers in practical use
• Boyle’s Law and its application
• Charles Law and its application
• The pressure law
• The general gas law

SPECIFIC OBJECTIVES:
By the end of the lesson, students should be able to:

1. Measure gas pressure using a barometer and manometer.
2. Explain Boyle’s Law and its application.
3. Describe Charles’s Law and its application.
4. Define the pressure law and explain its significance.
5. Derive and apply the general gas law.

INSTRUCTIONAL TECHNIQUES:

• Explanation
• Demonstration
• Questions and answers
• Hands-on activity: Measurement of gas pressure
• Video clips on gas laws and practical applications

INSTRUCTIONAL MATERIALS:

• Barometers
• Boyle’s Law apparatus
• Manometers
• Gas chamber
• Physics textbook
• Whiteboard markers
• Videos on gas laws and barometers

INSTRUCTIONAL PROCEDURES
PERIOD 1-5

PRESENTATION

STEP 1: INTRODUCTION

• The teacher will ask students about their understanding of gas pressure and its measurement.
• Students will share their prior knowledge, and the teacher will introduce the concept of gas pressure and the need for barometers.

STEP 2: EXPLANATION

• The teacher explains the concept of gas pressure and the devices used to measure it, such as barometers and manometers.
• Introduction to Boyle’s Law and Charles’s Law, emphasizing the relationship between pressure, volume, and temperature.
• The teacher explains the pressure law and how it relates to the general gas law.

STEP 3: DEMONSTRATION

• The teacher demonstrates how to use a barometer to measure atmospheric pressure.
• The teacher demonstrates Boyle’s Law using the Boyle’s Law apparatus, showing how pressure changes with volume.
• Demonstration of Charles’s Law, showing how the volume of a gas changes with temperature, using a gas chamber and a thermometer.

STEP 4: HANDS-ON ACTIVITY

• Students will measure gas pressure using manometers and barometers.
• Students will conduct experiments to observe Boyle’s Law by varying the volume of gas in a sealed container and measuring the pressure.
• Students will also observe Charles’s Law by heating or cooling a gas and recording its volume.

STEP 5: NOTE TAKING

• The teacher writes a summary note on the board, which students will copy.

NOTE
Gas Laws:

• Boyle’s Law: The pressure of a given mass of gas is inversely proportional to its volume at constant temperature.
• Formula: P1V1=P2V2P
• Charles’s Law: The volume of a given mass of gas is directly proportional to its absolute temperature at constant pressure.
• Formula: V1/T1=V2/T2
• Pressure Law: The pressure of a given mass of gas is directly proportional to its absolute temperature at constant volume.
• Formula: P1/T1=P2/T2
• General Gas Law: Combines Boyle’s, Charles’s, and the Pressure Law:
• Formula: PV/T=constant

EVALUATION

1. Define Boyle’s Law and Charles’s Law.
2. Explain the pressure law and its practical application.
3. Derive the general gas law.
4. What is the relationship between pressure and volume according to Boyle’s Law?

CLASSWORK:

• Solve problems involving Boyle’s Law and Charles’s Law.
• Calculate the pressure and volume of a gas at different temperatures using the general gas law.

CONCLUSION:

• The teacher will review the students' answers and provide feedback.

The students are encouraged to reflect on how gas laws are applied in everyday life, such as in weather balloons and automobile tires.