Parent plan · Week 12 · Reactions, Moles & Composition — connect, calculate and revise — Physical Science: Chemistry
Parent teaching plan · 36 weeksUnits to teach or revisit
Chapter 4 · Reactions, Moles & Composition
- Unit 4.3 · The Mole & Molar Mass
- Unit 4.4 · Percent Composition, Empirical & Molecular Formulas
- Unit 4.5 · Aqueous Reactions & Net Ionic Equations
Assigned readings
Develop this chapter question: What changes in a reaction, and what must be conserved?
This week’s goals
- Explain models, species, arrows and axes before substituting values.
- Conserve the relevant atoms, charge, amount and energy account.
- Apply independently, state limits and revise from evidence.
Read Bubbles, formulas and conserved quantities at chapter launch and revisit it alongside this week’s linked units, figures and investigation.
Five flexible sessions, normally 50–60 minutes. Two core unit sessions are scheduled, with a third for selected demanding topics. Sample week uses a complete 90-minute paper plus about 30 minutes of corrections within two ordinary-hour equivalents.
Session 1 · The Mole & Molar Mass — apply and explain
Use the linked chapter reading, unit explanations, figures and notebook.
Your task
Study Parts 3–4 and selected source-model prompts, then attempt the whole-unit application, illustrated practice and changed independent case. Explain a correction, revise the opening model and complete the exit check.
- Prepare the assigned explanation and identify the question.
- Trace a model or graph, labeling its species and units.
- Attempt the assigned reasoning and calculation before opening guidance.
- Compare with criteria and retain an explained correction.
Hint and response guidance
Name the species, quantities, boundary and assumptions before choosing a relationship. Use the matching figure to check each step.
n=22.0/44.0=0.500 mol CO₂. Molecules≈3.01×10²³. Each has two O atoms, giving 1.00 mol O atoms. Keep the entity labels through every conversion.
- Use the supplied evidence and correct species/units.
- Explain the relevant mechanism or relationship.
- Show intermediate working or a labeled model.
- State an assumption, limitation or useful next test.
Session 2 · Extended calculation and transfer — The Mole & Molar Mass
Use the linked chapter reading, unit explanations, figures and notebook.
Your task
Reconstruct a worked method without looking at its answer. Then solve this changed case, show intermediate steps and units, explain a limit and compare a second method where appropriate: Using Mₘ(CO₂)=44.0 g/mol and Nₐ≈6.022×10²³ mol⁻¹, find moles, molecules and moles of oxygen atoms in 22.0 g CO₂.
- Prepare the assigned explanation and identify the question.
- Trace a model or graph, labeling its species and units.
- Attempt the assigned reasoning and calculation before opening guidance.
- Compare with criteria and retain an explained correction.
Hint and response guidance
Name the species, quantities, boundary and assumptions before choosing a relationship. Use the matching figure to check each step.
n=22.0/44.0=0.500 mol CO₂. Molecules≈3.01×10²³. Each has two O atoms, giving 1.00 mol O atoms. Keep the entity labels through every conversion.
- Use the supplied evidence and correct species/units.
- Explain the relevant mechanism or relationship.
- Show intermediate working or a labeled model.
- State an assumption, limitation or useful next test.
Session 3 · Percent Composition, Empirical & Molecular Formulas — build the model
Use the linked chapter reading, unit explanations, figures and notebook.
Your task
Read the chapter background and unit language. Draw a first model, study the core explanation and Parts 1–2, trace each figure and attempt the visual questions/checks. Complete a first worked case with its answer covered.
- Prepare the assigned explanation and identify the question.
- Trace a model or graph, labeling its species and units.
- Attempt the assigned reasoning and calculation before opening guidance.
- Compare with criteria and retain an explained correction.
Hint and response guidance
Name the species, quantities, boundary and assumptions before choosing a relationship. Use the matching figure to check each step.
Carbon and other atoms have different masses; a mass ratio must be converted through molar masses to compare atom numbers. The empirical formula counts atoms; converting to proportional mole amounts removes the unequal per-atom masses.
- Use the supplied evidence and correct species/units.
- Explain the relevant mechanism or relationship.
- Show intermediate working or a labeled model.
- State an assumption, limitation or useful next test.
Session 4 · Percent Composition, Empirical & Molecular Formulas — apply and explain
Use the linked chapter reading, unit explanations, figures and notebook.
Your task
Study Parts 3–4 and selected source-model prompts, then attempt the whole-unit application, illustrated practice and changed independent case. Explain a correction, revise the opening model and complete the exit check.
- Prepare the assigned explanation and identify the question.
- Trace a model or graph, labeling its species and units.
- Attempt the assigned reasoning and calculation before opening guidance.
- Compare with criteria and retain an explained correction.
Hint and response guidance
Name the species, quantities, boundary and assumptions before choosing a relationship. Use the matching figure to check each step.
Amounts are 1.25 mol Fe and 1.875 mol O, ratio 1:1.5, hence Fe₂O₃. Assume the analyzed sample is one oxide accounted for by those elements and the input precision supports that ratio.
- Use the supplied evidence and correct species/units.
- Explain the relevant mechanism or relationship.
- Show intermediate working or a labeled model.
- State an assumption, limitation or useful next test.
Session 5 · Aqueous Reactions & Net Ionic Equations — build the model
Use the linked chapter reading, unit explanations, figures and notebook.
Your task
Read the chapter background and unit language. Draw a first model, study the core explanation and Parts 1–2, trace each figure and attempt the visual questions/checks. Complete a first worked case with its answer covered.
- Prepare the assigned explanation and identify the question.
- Trace a model or graph, labeling its species and units.
- Attempt the assigned reasoning and calculation before opening guidance.
- Compare with criteria and retain an explained correction.
Hint and response guidance
Name the species, quantities, boundary and assumptions before choosing a relationship. Use the matching figure to check each step.
The separate solid phase is the product being represented; splitting it as aqueous ions would remove the phase change from the equation. They remain in the aqueous phase in this selected account; cancellation removes them only from the compact equation.
- Use the supplied evidence and correct species/units.
- Explain the relevant mechanism or relationship.
- Show intermediate working or a labeled model.
- State an assumption, limitation or useful next test.
Submit this week
- Labeled first/revised models and intermediate calculations.
- Assigned practice and assessed attempts with explained corrections.
- Investigation record/report when assigned, identifying supplied versus collected data.
Parent / teacher weekly conference
Use actual written work to adjust support. Do not count a copied solution as independent mastery. Extend or redistribute time where needed; home-study records do not certify supervised or mandated laboratory requirements.
- Can each relevant symbol and unit be explained?
- Does the calculation conserve the appropriate quantities?
- Can the learner solve a changed case and explain an assumption?