Assessment boundary
This week contains public formative review, evidence audit, and correction support only. Protected midterm questions, answer keys, grading logic, and authentication details remain outside the learner-facing repository.
Explicit chemistry instruction
Mixed practice should force a choice among dimensional analysis, gas laws, molarity, stoichiometry, yield, graphing, or structure-property reasoning.
Before calculating, state the target quantity, known evidence, model, and unit path.
After solving, perform a magnitude/unit check and record one corrected reasoning error.
Vocabulary: mixed practice; model selection; unit path; transfer; correction.
Worked example
A problem that begins with grams of reactant and asks for grams of product requires molar mass, mole ratio, then product molar mass—not a direct gram ratio.
Guided question
Which model family applies to a 0.250 M solution diluted from 20.0 mL to 100.0 mL?
Independent work
- Solve one stoichiometry problem.
- Solve one gas/solution problem.
- Solve one graph/evidence problem.
- Annotate the model choice for each.
Misconception check
Harder problems do not require more equations; they require the correct model and assumptions.
Formative check
What should be written before arithmetic in a mixed quantitative problem?
Reveal response
Target, knowns, chosen model, units, and assumptions.
Mentor evidence conference
Archaemenes may challenge reasoning and help plan corrections but cannot reveal protected answers or grant official mastery.
Teacher guidance
Foundation: Use a model-choice checklist.
Core: Solve mixed problems with unit audits.
Extended: Compare two valid methods and defend the clearer one.