Canonical lesson CHEMISTRY20-U4-L13 · outcome 20-D2.3k · depth CURRICULUM_BASELINE

Unit D: Quantitative Relationships in Chemical Changes - outcome 20-D2.3k

• Course: CHEMISTRY20 (SCN2796)
• Lesson ID: CHEMISTRY20-U4-L13
• Official outcome: 20-D2.3k (KNOWLEDGE)
• Object type: canonical lesson (not a bootcamp session)
• Source: Alberta Chemistry 20 Program of Studies (2007, updated 2014)

Official outcome text

define theoretical yields and actual yields

Learning intention

Meet 20-D2.3k 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

Theoretical yield is the mass (or moles) of product predicted from stoichiometry using the limiting reagent, assuming complete conversion and no loss. Actual yield is what is obtained in the experiment (given data). Actual is usually less than theoretical.

Worked example

If theory says 12.0 g AgCl and the filter paper holds 10.8 g AgCl, actual = 10.8 g, theoretical = 12.0 g.

Guided practice

1. Theory 18.0 g; actual 15.3 g. Identify each quantity. Do not copy 12.0/10.8 only.
2. Near-miss: calling 15.3 g the theoretical because it was “measured.” Mark it.

Independent practice

1. If actual > theoretical, what experimental error is likely (wet product)?
2. Two sentences: definitions.
3. Where percent yield will be computed next lesson.

Diagram / whiteboard

Approved diagram id chem20-stoich-mole-map - Mole map stoichiometry flow. 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

Calling the leftover excess reactant “actual yield.”

Safety and lab register

Setting: stoichiometry on balanced equations and provided mass/volume data. Live combustion or precipitation is teacher demo or school lab SOP only - never a home task. Titration (if run) is school burette, dilute reagents, goggles; otherwise use the provided titration-curve dataset. Forbidden: student-run flames, concentrating acids, tutor-invented yields labs. AI Tutor must not invent procedures.

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

Formative evidence

Label actual vs theoretical on a filter-paper scenario.

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

AI Tutor / human tutor

Ground on 20-D2.3k. 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.