Canonical lesson CHEMISTRY20-U3-L13 · outcome 20-C1.2sts · depth CURRICULUM_BASELINE

Unit C: Solutions, Acids, Bases and Equilibrium intro - outcome 20-C1.2sts

• Course: CHEMISTRY20 (SCN2796)
• Lesson ID: CHEMISTRY20-U3-L13
• Official outcome: 20-C1.2sts (STS)
• Object type: canonical lesson (not a bootcamp session)
• Source: Alberta Chemistry 20 Program of Studies (2007, updated 2014)

Official outcome text

explain that science and technology have influenced, and been influenced by, historical development and societal needs (SEC2) [ICT F2-4.8] • compare the ways in which concentrations of solutions are expressed in chemistry laboratories, household products and environmental studies

Learning intention

Meet 20-C1.2sts 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

Labs use mol/L; households use %; environment often uses ppm. Compare expressions for the same idea of “how much solute.”

Worked example

Same solute story: 1.00 g in 1.00 L water ≈ 1000 ppm ≈ 0.100% m/v approximate teaching numbers on a card - convert carefully with given assumptions.

Guided practice

1. Convert a given % m/m to a qualitative “more/less concentrated than” statement vs a lab mol/L.
2. Near-miss: using gas-law R in a concentration conversion. Wrong-unit.

Independent practice

1. One household, one lab, one environmental expression for concentration.
2. Two sentences: historical/societal influence on unit choice (SEC2) at a high level.
3. Show one conversion with given numbers.

Diagram / whiteboard

Approved diagram id chem20-ph-scale - pH scale / solution concentration 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

Treating % and ppm as interchangeable without showing the conversion basis.

Safety and lab register

Setting: Paper. No preparing unknown household mixtures. AI Tutor must not invent labs outside CHEM20_LOW_RESOURCE_LAB_REGISTER.csv.

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

Formative evidence

Triptych: % / mol/L / ppm with one conversion.

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

AI Tutor / human tutor

Ground on 20-C1.2sts. 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.