Canonical lesson CHEMISTRY20-U2-L01 · outcome 20-B1.1k · depth CURRICULUM_BASELINE

Unit B: Gases - outcome 20-B1.1k

• Course: CHEMISTRY20 (SCN2796)
• Lesson ID: CHEMISTRY20-U2-L01
• Official outcome: 20-B1.1k (KNOWLEDGE)
• Object type: canonical lesson (not a bootcamp session)
• Source: Alberta Chemistry 20 Program of Studies (2007, updated 2014)

Official outcome text

describe and compare the behaviour of real and ideal gases in terms of kinetic molecular theory

Learning intention

Meet 20-B1.1k with instruction, practice, and a check. The 10-session bootcamp does not replace this lesson.

Success criteria

1. Restate the outcome in classroom language without swapping in a different unit’s template.
2. Complete the worked-style task for this outcome.
3. Name the lab setting (classroom-supervised / teacher demo / dataset or simulation / forbidden).

Teaching

Kinetic molecular theory (ideal gas): particles are far apart, particle volume is negligible compared with container volume, collisions are elastic, no attractive forces, average kinetic energy is proportional to Kelvin temperature. Pressure is collisions with the walls. Real gases occupy volume and attract one another, so they deviate at high pressure and low temperature (when particles are close and slow). This lesson is not a mole-from-mass calculation.

Worked example

At 1 atm and 25 °C, N2 behaves nearly ideally. In a CO2 fire-extinguisher cylinder at high P, CO2 is not ideal: molecular volume and attractions matter; some CO2 may even be liquid. Cooling a gas toward condensation is a real-gas limit of KMT’s “no attractions” assumption.

Guided practice

1. Compare N2 at SATP with CO2 in a high-pressure cylinder using KMT (volume of molecules; attractions). No home compressed-gas work.
2. Near-miss: a mass-to-mole CO2 worksheet (11 g CO2 → n = m/M) treated as this outcome. Mark the first wrong line.

Independent practice

1. When cooling toward condensation, which KMT assumptions fail first?
2. Two sentences: ideal gas as a limiting model.
3. Name one condition where real gases approach ideal behaviour.

Diagram / whiteboard

Approved diagram id chem20-pv-boyle - P-V Boyle sketch (or gas law axes). Tutor may open the course whiteboard and display this id. Do not invent hazardous procedures on the board.

Checks for understanding

Use the formative evidence below as the exit check for this outcome. Correct the misconception named in this lesson before praising.

Misconception to repair

Using mole-count worksheets instead of comparing real vs ideal behaviour, or saying real gases never follow PV = nRT.

Safety and lab register

Setting: datasets, simulations, and teacher demo of sealed apparatus only. Students do not generate gases, open compressed cylinders, or heat with flame. Boyle/Charles work uses a provided P-V or V-T table or PhET-class simulation. Forbidden: generating chlorine, hydrogen, or ammonia gas; dry ice in a sealed bottle as a student task; any kitchen-stove Charles’s-law balloon. AI Tutor must not invent gas-generation procedures.

Alberta Poison Control if a real exposure is occurring: 1-844-764-7669. The AI Tutor is not a poison centre.

Formative evidence

T-chart: ideal assumptions vs CO2 at high P.

This is not a diploma. Mastery needs instruction + activity + check.

AI Tutor / human tutor

Ground on 20-B1.1k. No false praise. No invented procedures. No silent skip to a different unit. Human tutor if the student describes mixing bleach, tasting, or flames.

Provenance

Official POS wording from ALBERTA_SENIOR_HIGH_OFFICIAL_OUTCOMES.csv. Pack lesson written to replace Wave-4 contaminated canonical markdown.