Module 2 Review
The complete reference for Module 2, Introduction to Quantitative Chemistry. Every formula, every key term, every exam question type, and worked examples of each. Use this as your study reference before the module quiz and the HSC.
Practise this lesson
Four printable worksheets that build from the foundations up to exam-style questions, start at whatever level suits you.
Without looking at any notes, can you list the four key formulas that connect moles (n) to mass, particles, gas volume, and concentration? And which single concept acts as the "universal bridge" that links every calculation in this module?
Key facts
- The four Module 2 inquiry questions and what each covers
- Core formulas: n = m ÷ MM, N = n × Nₐ, V = n × Vₘ, n = c × V, PV = nRT
- STP = 22.71 L/mol; SATP = 24.8 L/mol; concordant titres within 0.10 mL
Concepts
- How the mole links mass, particles, gas volume and concentration
- When to apply purity, percentage yield, limiting reagent and the gas laws
- Why a true yield is ≤ 100% and an apparent value above 100% signals error
Skills
- Solve multi-step problems that chain several inquiry questions
- Choose the correct molar volume and convert temperatures to kelvin
- Check answers for physical plausibility (yield ≤ 100%, concordant titres)
Common errors · the 3 traps that cost marks
Misconception to fix
Wrong: Concentration and amount of solute are the same thing.
Misconception to fix
Right: Concentration is amount per unit volume; the same amount of solute can produce different concentrations in different volumes.
Applying purity and yield at the wrong stage
Percentage purity must be applied to the impure sample mass before converting to moles, while percentage yield is applied only at the very end (to the theoretical product). Students often calculate moles from the full impure mass, or multiply by yield too early, which makes every downstream value wrong.
Fix: Follow the order: impure mass → pure mass (× % purity) → moles → mole ratio → theoretical product → × % yield. Purity first, yield last.
Quick-fire practice · 5 reps +2 XP per reveal
Calculate the mass of 0.25 mol of calcium carbonate, CaCO₃. (M = 100.09)
A solution contains 0.40 mol of NaCl dissolved in 250 mL. Calculate its concentration in mol L⁻¹.
A 3.0 L sample of gas at 100 kPa is compressed at constant temperature until the pressure is 150 kPa. Find the new volume.
How many molecules are present in 8.0 g of methane, CH₄? (M = 16.0)
Complete combustion CH₄ + 2O₂ → CO₂ + 2H₂O: what volume of CO₂ (25 °C, 100 kPa) forms from 0.50 mol of CH₄? (Vₘ = 24.79 L mol⁻¹)
At the start of this lesson, you tried to recall the four key formulas and identify the concept that bridges all of Module 2.
The mole (n) is the universal bridge, every formula in Module 2 converts something into moles or from moles: n = m ÷ MM (mass), N = n × Nₐ (particles), V = n × molar volume (gas), and n = c × V (solution). Every calculation, whether IQ1, IQ2, IQ3 or IQ4 (the gas laws, where n appears in PV = nRT), passes through n as the central intermediate step. If you can automatically and accurately perform each of these four conversions, the rest of every stoichiometry or concentration problem follows.
Reflect: how did your initial thinking compare to what you've learned?
Write a reflection in your workbook.
Pick your answer, then rate your confidencethat tells the system what to drill next.
Five timed questions on module 2 review. Beat the boss to bank a tier, gold (perfect + fast), silver (80%+), or bronze (cleared).
⚔ Enter the arenaClimb platforms, hit checkpoints, and answer questions on this lesson's topic.
Mark lesson as complete
Tick when you've finished the practice and review.
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