Matter and Its Properties · SHS1 Chemistry

Lesson notes

Learning Objectives

Indicator: 1.1.1.LI.3 - State Graham’s law of diffusion/effusion and Dalton’s law of partial pressures and apply them to perform calculations.

By the end of the lesson, learners can:

State Graham’s law of diffusion/effusion in their own words and write the mathematical relationship between rate of diffusion, molar mass, and density of gases.
Perform calculations using Graham’s law to compare the rates of diffusion/effusion of two gases when given their molar masses or densities.
State Dalton’s law of partial pressures in their own words and explain its meaning in terms of gas particles in a mixture.
Calculate the total pressure of a gas mixture given the partial pressures of individual gases, or find the partial pressure of one gas given the total pressure and the other partial pressures.
Use the kinetic theory of matter, first introduced in the kinetic theory of solids, liquids and gases, to explain why lighter gases diffuse faster than heavier gases at the same temperature.

Sign in with your phone number to read the full note and download the GES plan - free.

Sign in with phone number

Curriculum details

Strand: Physical Chemistry (Strand 1)
Sub-strand: Matter and Its Properties (1.1)
Content standard: 1.1.1.CS.3 - Demonstrate understanding of the use of the kinetic theory of matter to explain the behaviour of solids, liquids and gases under different conditions and describe the laboratory preparation of gases as well as their uses in everyday life. 1.1.1.LO.1 Use the knowledge and understanding of the scientific practices in Chemistry to explain the structure of the atom as well as the stability of its nucleus. 1.1.1.LO.2 Use the mole concept to determine the amount and quantity of various substances involved in chemical reactions. 1.1.1.LO.3 Write mole ratios for chemical equations and apply it in quantitative analysis. 1.1.1.LO.4 Use the kinetic theory of matter to explain the behaviour of solids, liquids and gases under different conditions and describe the laboratory preparation of gases as well as their uses in everyday life.
Indicator: 1.1.1.LI.3 - State Graham's law of diffusion/effusion and Dalton's law of partial pressures and apply them to perform calculations.
Suggested placement: Semester 1, Week 20 (Week 20 of the year)
Our suggestion, laid out in curriculum order across three terms of twelve weeks. NaCCA does not fix the week, so follow your school's scheme of learning.
Curriculum reference: NaCCA curriculum document, p. 39

Exemplars (from the NaCCA curriculum)

Talk for Learning: In small mixed-ability groups,
- Discuss Graham's law of diffusion/effusion and use it to describe and explain the effect of relative molecular mass and/or density on the rate of diffusion/effusion of gases.
- Explain Dalton's law of partial pressures and its application in determining the total pressure of a mixture of gases or the partial pressure exerted by each component in a mixture of gases.
Experiential Learning:
- Design and perform an experiment to investigate the rate of diffusion of gaseous ammonia and hydrogen chloride.
- Make deductions from the results of the experiment.
Problem Solving Approach: Perform calculations involving diffusion/effusion as well as Dalton's partial law of pressure.
Teaching and Learning Materials:
- apparatus * Chart to illustrate the behaviour of particles * [Simulations (PHET), video, virtual laboratory can be used here] * Graph board * Graph sheets * Long cylindrical transparent glass tube * Small wads cotton wool * Forceps or bungs (to fit into the ends of the glass tube) * Conc. HCl and Conc. NH
- 3
- * Protective gloves * * Retort stand with clamps * Strip of universal indicator paper * *
- Calculator * Worksheets with steps for the calculation
- Gas preparation kits
- Wooden splint
- water * Marble chips
- Hydrochloric acid * Magnesium ribbon
- Calcium hydroxide * Ammonium chloride etc.
- Universal litmus paper
Assessment (1.1.1.AS.3). The document marks these depth-of-knowledge levels for this indicator: Level 4 Extended critical thinking and reasoning.