Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
At fixed volume, pressure is 120 kPa at 300 K. Find pressure at 350 K. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
A gas pressure ratio can always use Celsius temperatures. This claim is false: An ideal gas is a model with conditions of validity. Celsius zero is not zero molecular motion, and internal energy is not determined by pressure alone.
Key:
Gas models and absolute temperature: At fixed amount and volume, pressure is proportional to kelvin temperature. At fixed temperature and amount, pressure is inversely proportional to volume. State which quantities are fixed before choosing a relationship.
| English | 中文 | 拼音 |
|---|---|---|
| absolute temperature/ˈæbsəluːt ˈtemprɪtʃə/ | 绝对温度 | jué duì wēn dù |
| ideal gas/aɪˈdɪəl ɡæs/ | 理想气体 | lǐ xiǎng qì tǐ |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
An atom has atomic number 17 and mass number 35. Find its number of neutrons. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
All covalent substances have low melting points. This claim is false: Melting a simple molecular substance usually overcomes intermolecular attractions; it does not require breaking all covalent bonds within each molecule.
Key:
Particles, bonding and bulk properties: To explain a bulk property, name the structure, particles, forces and mobile charge carriers. Simple molecular substances can have strong covalent bonds inside molecules but weak attractions between molecules.
| English | 中文 | 拼音 |
|---|---|---|
| ionic bond/aɪˈɒnɪk bɒnd/ | 离子键 | lí zi jiàn |
| delocalized electron/dɪˈlɒkəlaɪzd ɪˈlektrɒn/ | 离域电子 | lí yù diàn zi |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
Calculate amount in 5.0 g of a substance with molar mass 100 g per mole. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
Balanced equation coefficients always give reactant mass ratios. This claim is false: Excess acid means acid does not limit the stated calculation. A coefficient of 2 before HCl does not double the hydrogen amount.
Key:
Amounts, equations and limiting reagents: Calculate the amount available for each reactant and divide by its coefficient. The smaller ratio limits the reaction. Use that reactant to calculate the maximum product before comparing actual yield.
| English | 中文 | 拼音 |
|---|---|---|
| limiting reagent/ˈlɪmɪtɪŋ rɪˈeɪdʒənt/ | 限量试剂 | xiàn liàng shì jì |
| mole/məʊl/ | 摩尔 | mó ěr |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
How many moles of bromine react completely with 0.15 mol ethene? Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
Compounds with the same molecular formula always have identical properties. This claim is false: Bromine decolourization provides evidence of unsaturation in an appropriate test. It is not proof that an unknown sample is specifically ethene.
Key:
Organic structures and reaction pathways: Distinguish addition, substitution, oxidation and polymerization by tracing bonds before and after reaction. Conditions and reagents belong to the reaction arrow; they are not interchangeable labels.
| English | 中文 | 拼音 |
|---|---|---|
| functional group/ˈfʌŋkʃənl ɡruːp/ | 官能团 | guān néng tuán |
| isomer/ˈaɪsəmə/ | 异构体 | yì gòu tǐ |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
50 g water rises 4 °C. Use c = 4.2 J per gram per degree to find q. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
Bond breaking releases energy. This claim is false: Heat loss usually lowers the observed temperature rise. The solution gaining heat and the reaction losing heat have opposite signs.
Key:
Calorimetry and chemical energy: Use energy transferred = mass × specific heat capacity × temperature change. Convert joules to kilojoules before dividing by reaction amount. An exothermic molar enthalpy change has a negative sign.
| English | 中文 | 拼音 |
|---|---|---|
| enthalpy change/enˈθælpi tʃeɪndʒ/ | 焓变 | hán biàn |
| exothermic/eɡzəˈðɜːmɪk/ | 放热的 | fàng rè de |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
A reusable item costs 600 energy units initially and 5 per use; disposables cost 35 per use. Find break-even uses. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
A recyclable product is always recycled after use. This claim is false: A break-even model is sensitive to cleaning, transport and disposal assumptions. Recyclable does not guarantee that an item is actually collected and recycled.
Key:
Atmosphere, resources and life-cycle decisions: Define the functional unit before comparing products. The same delivered service, such as carrying one litre of water a hundred times, is fairer than comparing one object with another regardless of lifetime.
| English | 中文 | 拼音 |
|---|---|---|
| life-cycle assessment/laɪf ˈsaɪkl əˈsesmənt/ | 生命周期评价 | shēng mìng zhōu qī píng jià |
| functional unit/ˈfʌŋkʃənl ˈjuːnɪt/ | 功能单位 | gōng néng dān wèi |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
ΔH=30 kJ per mole, ΔS=0.10 kJ per kelvin per mole and T=400 K. Find ΔG. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
A thermodynamically favourable reaction must be fast. This claim is false: Thermodynamic favourability does not establish reaction rate. Celsius cannot replace kelvin in TΔS, and a unit conversion error can change the result by a factor of 1,000.
Key:
Entropy, Gibbs energy and feasibility: Use ΔG = ΔH - TΔS with consistent energy units. A negative Gibbs energy change indicates thermodynamic favourability for the stated conditions, not a fast rate. An activation barrier can make a favourable process slow.
| English | 中文 | 拼音 |
|---|---|---|
| entropy/ˈentrəpi/ | 熵 | shāng |
| Gibbs energy/ɡɪbz ˈenədʒi/ | 吉布斯能 | jí bù sī néng |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
Burette readings are 1.40 and 23.65 cubic centimetres. Calculate titre. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
A flask must be rinsed with analyte to avoid dilution of its mole amount. This claim is false: Adding distilled water to the flask changes volume but not the transferred amount of analyte. Do not average a rough titre with carefully measured concordant values.
Key:
Titration and a defensible concentration: Calculate the known amount first, apply the stoichiometric ratio, then divide by the unknown solution volume in cubic decimetres. Use concordant titres as required by the school method and report the accepted values.
| English | 中文 | 拼音 |
|---|---|---|
| titre/ˈtɪtə/ | 滴定体积 | dī dìng tǐ jī |
| equivalence point/ɪˈkwɪvələns pɔɪnt/ | 化学计量点 | huà xué jì liàng diǎn |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
A reaction makes 24 cubic centimetres of gas in 40 s. Find average rate. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
A faster reaction always produces a larger final amount of product. This claim is false: A catalyst does not change the equilibrium constant at a fixed temperature. A mass-loss method cannot detect all reactions, and losing gas through a leak biases a collection experiment.
Key:
Rates, catalysts and reliable endpoints: A product-time graph has a steeper gradient where rate is larger. A tangent estimates instantaneous rate; a secant gives average rate over an interval. The final plateau reflects the total collected product under the stated conditions.
| English | 中文 | 拼音 |
|---|---|---|
| rate/reɪt/ | 速率 | sù lǜ |
| activation energy/ˌæktɪˈveɪʃn ˈenədʒi/ | 活化能 | huó huà néng |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
For A ⇌ B, calculate [B]/[A] when [B]=0.8 and [A]=0.2. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
A catalyst changes the equilibrium constant at a fixed temperature. This claim is false: Do not use a catalyst to claim a larger equilibrium yield. For heterogeneous equilibria, pure solids are omitted from the usual equilibrium expression.
Key:
Equilibrium and changing conditions: A concentration or pressure change disturbs the balance. The system responds toward a new equilibrium. Temperature changes can also change the equilibrium constant; a catalyst changes how quickly equilibrium is reached.
| English | 中文 | 拼音 |
|---|---|---|
| reversible reaction/rɪˈvɜːsɪbl rɪˈækʃn/ | 可逆反应 | kě nì fǎn yìng |
| equilibrium/ˌiːkwɪˈlɪbrɪəm/ | 平衡 | píng héng |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
How many moles of electrons reduce 0.20 mol of Cu²⁺ to copper? Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
Reduction means loss of electrons. This claim is false: Electrode signs depend on the cell type. In an electrolytic cell the cathode is negative; reduction remains the defining process at a cathode in every cell.
Key:
Redox and electrolysis: Predict products using the specified electrolyte and electrode material. In an aqueous solution, hydrogen or oxygen may form because water-related species compete. Molten salts contain only the ions of the salt.
| English | 中文 | 拼音 |
|---|---|---|
| oxidation/ˌɒksɪˈdeɪʃn/ | 氧化 | yǎng huà |
| reduction/rɪˈdʌkʃn/ | 还原 | huán yuán |
Supported HL focus. First assessment 2025; current brief acquired; full Chemistry guide not acquired. Remaining guide, assessment and practical requirements retain their recorded holds.
Prerequisites: read the stated quantities and units, use arithmetic and the model conditions below. Each lesson develops its own method before independent transfer.
These are original or explicitly fictional teaching examples, not actual measurements or completed assessed learner investigations.
Example:
A 40 cm reading has an absolute uncertainty of 1 cm. Find percentage uncertainty. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Warn:
Repeating a measurement always removes a calibration offset. This claim is false: Repeating readings reduces random uncertainty in a mean but does not automatically remove a zero error. Do not quote more decimal places than your measurement can support.
Key:
Uncertainty, gradients and model testing: For a product or quotient, adding fractional uncertainties is a common maximum-uncertainty approximation. For a difference, add absolute uncertainties. A nonzero intercept can reveal an offset or an incomplete model.
| English | 中文 | 拼音 |
|---|---|---|
| systematic error/ˌsɪstəˈmætɪk ˈerə/ | 系统误差 | xì tǒng wù chā |
| uncertainty/ʌnˈsɜːtənti/ | 不确定度 | bù què dìng dù |
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