Canonical lesson CHEMISTRY20-U3-L11 · outcome 20-C1.11k · depth CURRICULUM_BASELINE

Unit C: Solutions, Acids, Bases and Equilibrium intro - outcome 20-C1.11k

• Course: CHEMISTRY20 (SCN2796)
• Lesson ID: CHEMISTRY20-U3-L11
• Official outcome: 20-C1.11k (KNOWLEDGE)
• Object type: canonical lesson (not a bootcamp session)
• Source: Alberta Chemistry 20 Program of Studies (2007, updated 2014)

Official outcome text

describe the procedures and calculations required for preparing and diluting solutions

Learning intention

Meet 20-C1.11k 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

Preparing a standard solution: mass solute, dissolve, transfer, dilute to the mark in a volumetric flask, mix. Diluting: pipette stock, dilute to mark. Rinse, meniscus at eye level, read the calibration line. Safety: goggles; no tasting; no concentrated acid at home.

Worked example

To make 250.0 mL of 0.100 mol/L Na2CO3 (M = 106.0 g/mol): n = 0.02500 mol, m = 2.650 g, dissolve, dilute to 250.0 mL. Then c1V1 = c2V2 if a further dilution is required.

Guided practice

1. Write the flask procedure for 100.0 mL of 0.200 mol/L KCl (M = 74.6 g/mol): mass, dissolve, dilute to mark. Do not copy the 2.650 g Na2CO3 numbers.
2. Near-miss: measuring 100 mL of water then dumping in solute without a volumetric flask (school). Mark the limitation.

Independent practice

1. Then dilute 10.00 mL of that solution to 50.00 mL - find c2.
2. WHMIS: where the SDS/label is checked in the plan (before weighing).
3. Setting: school glassware; dataset alternative if no flask.

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

Filling to the mark with undissolved solid still in the neck, or using a beaker as if it were volumetric.

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

Numbered procedure + one mass calculation.

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

AI Tutor / human tutor

Ground on 20-C1.11k. 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.