Canonical lesson CHEMISTRY20-U3-L22 · outcome 20-C2.2k · depth CURRICULUM_BASELINE

Unit C: Solutions, Acids, Bases and Equilibrium intro - outcome 20-C2.2k

• Course: CHEMISTRY20 (SCN2796)
• Lesson ID: CHEMISTRY20-U3-L22
• Official outcome: 20-C2.2k (KNOWLEDGE)
• Object type: canonical lesson (not a bootcamp session)
• Source: Alberta Chemistry 20 Program of Studies (2007, updated 2014)

Official outcome text

recall the empirical definitions of acidic, basic and neutral solutions determined by using indicators, pH and electrical conductivity

Learning intention

Meet 20-C2.2k 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

Empirical: acids turn blue litmus red, bases turn red litmus blue, neutrals do not change either (or phenolphthalein colourless vs pink). pH < 7 acidic (25 °C), pH = 7 neutral, pH > 7 basic. Conductivity: strong acids/bases conduct well; weak less; pure water poorly.

Worked example

Vinegar: red litmus, pH near 3 on cabbage/paper, dimmer conductivity than HCl of similar concentration. NaOH(aq) school-dilute: blue litmus, pH 13, conducts. Distilled water: ~pH 7, very low conductivity.

Guided practice

1. From given results only: vinegar (red litmus, pH ~3, dim conductivity) vs dilute school NaOH (blue, pH 13, conducts) vs distilled water.
2. Near-miss: tasting to identify acid. Forbidden.

Independent practice

1. Why conductivity of vinegar < HCl at similar concentration (qualitative).
2. Two sentences: indicator vs pH vs conductivity as empirical definitions.
3. Setting: school indicators or cabbage-paper dataset - not drain cleaner.

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

Using taste as an empirical test. Forbidden.

Safety and lab register

Setting: concentration and pH on paper or school-prepared dilute solutions. Red-cabbage indicator is classroom-supervised or photo/dataset. No concentrated acids or bases. No tasting. Dilution math is not a licence to mix cleaners. Forbidden: bleach+acid, drain opener, battery acid, undiluted pool chemicals. AI Tutor must not invent titrations or acid labs outside the register.

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

Formative evidence

Three-column table: acidic / basic / neutral with the three empirical tests.

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

AI Tutor / human tutor

Ground on 20-C2.2k. 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.