📚 IGCSE OCR Chemistry: End-of-Term Revision Guide | IGCSE OCR 化学：期末复习提纲
As the term draws to a close, consolidating your understanding of the IGCSE OCR Chemistry syllabus is essential for exam success. This revision guide breaks down the core topics into manageable sections, highlighting key definitions, equations, and common pitfalls. Use it as a checklist to structure your final review sessions.
期末临近，巩固 IGCSE OCR 化学课程的理解对于考试成功至关重要。本复习提纲将核心主题分解为易于掌握的单元，突出关键定义、方程式和常见误区。你可以把它当作一份清单，用来规划最后的复习进度。
1. Atomic Structure | 原子结构
Atoms contain a small, dense nucleus composed of protons (positive) and neutrons (neutral), surrounded by electrons in shells.
原子由一个体积极小、密度很大的原子核组成，核内包含质子（带正电）和中子（不带电），核外电子分布在能层中。
The atomic number (Z) is the number of protons, which defines the element. The mass number (A) is the total number of protons and neutrons.
原子序数 (Z) 是质子数，决定了元素的种类。质量数 (A) 是质子数和中子数的总和。
Isotopes are atoms of the same element with different numbers of neutrons. They have identical chemical properties but different physical properties.
同位素是同一种元素中中子数不同的原子。它们的化学性质相同，但物理性质不同。
- Relative atomic mass (Aᵣ) is the weighted average mass of an atom compared to ¹/₁₂ the mass of carbon-12.
- 相对原子质量 (Aᵣ) 是一个原子的加权平均质量与碳-12 原子质量的 ¹/₁₂ 相比的比值。
2. Chemical Bonding | 化学键
Ionic bonding occurs between metals and non‑metals. Metals lose electrons to form positive ions (cations); non‑metals gain electrons to form negative ions (anions).
离子键存在于金属和非金属之间。金属原子失去电子形成阳离子；非金属原子得到电子形成阴离子。
The formula of an ionic compound shows the simplest whole‑number ratio of ions. The total positive charge and total negative charge must be equal.
离子化合物的化学式表示离子的最简整数比。总正电荷与总负电荷必须相等。
Covalent bonding involves atoms sharing electron pairs. Simple molecular substances (e.g. H₂O, CO₂) have low melting and boiling points due to weak intermolecular forces.
共价键涉及原子间共用电子对。简单分子物质（如 H₂O、CO₂）由于分子间作用力较弱，熔点和沸点较低。
Giant covalent structures, such as diamond and silicon dioxide, have very high melting points because of strong covalent bonds throughout the lattice. Graphite conducts electricity due to delocalised electrons between layers.
巨型共价结构，如金刚石和二氧化硅，因整个晶格中存在强共价键而具有很高的熔点。石墨因其层间的离域电子而能导电。
3. Stoichiometry | 化学计量学
The mole is the unit for amount of substance. One mole contains 6.02 × 10²³ particles (Avogadro constant).
摩尔是物质的量的单位。1 摩尔含有 6.02 × 10²³ 个粒子（阿伏伽德罗常数）。
moles = mass (g) / molar mass (g/mol)
物质的量 (mol) = 质量 (g) / 摩尔质量 (g/mol)
Empirical formula gives the simplest whole‑number ratio of atoms. Molecular formula gives the actual number of atoms in a molecule.
实验式给出原子的最简整数比。分子式给出分子中原子的实际数量。
Reacting mass calculations require a balanced equation. Convert masses to moles, use the mole ratio, and convert back to mass.
反应质量计算需要配平的化学方程式。先将质量转换为物质的量，利用物质的量之比，再转换回质量。
4. Acids, Bases & Salts | 酸、碱和盐
An acid is a proton (H⁺) donor; a base is a proton acceptor. Alkalis are soluble bases that release OH⁻ ions in water.
酸是质子 (H⁺) 的供体；碱是质子的受体。碱溶于水释放 OH⁻ 离子，称为可溶性碱。
Neutralisation: H⁺ + OH⁻ → H₂O. Acid + metal oxide/hydroxide → salt + water. Acid + carbonate → salt + water + CO₂.
中和反应：H⁺ + OH⁻ → H₂O。酸 + 金属氧化物/氢氧化物 → 盐 + 水。酸 + 碳酸盐 → 盐 + 水 + CO₂。
pH scale measures acidity (0‑6 acidic, 7 neutral, 8‑14 alkaline). Universal indicator or a pH probe can be used.
pH 值用于衡量酸碱度（0‑6 为酸性，7 为中性，8‑14 为碱性）。可使用通用指示剂或 pH 探头进行测定。
Preparing soluble salts: use acid + insoluble base/metal/carbonate; filter off excess solid, then crystallise.
可溶性盐的制备：用酸与不溶性碱/金属/碳酸盐反应；滤出过量固体，然后结晶。
5. Redox and Electrolysis | 氧化还原与电解
Oxidation is the loss of electrons, reduction is the gain of electrons (OIL RIG). A substance that is oxidised acts as a reducing agent.
氧化是失去电子，还原是得到电子（OIL RIG）。被氧化的物质充当还原剂。
Electrolysis splits an ionic compound using direct current. Positive ions (cations) move to the cathode (negative electrode); negative ions (anions) move to the anode (positive electrode).
电解是利用直流电分解离子化合物。阳离子移向阴极（负极）；阴离子移向阳极（正极）。
In aqueous solutions, the product at each electrode depends on the reactivity of the ions. At the cathode, the less reactive element (metal or hydrogen) is discharged. At the anode, halide ions (Cl⁻, Br⁻, I⁻) are discharged before OH⁻ unless the solution is very dilute.
在水溶液中，各电极的生成物取决于离子的活泼性。在阴极，较不活泼的元素（金属或氢）优先放电。在阳极，卤素离子（Cl⁻、Br⁻、I⁻）比 OH⁻ 优先放电，除非溶液极稀。
6. Energy Changes | 能量变化
Exothermic reactions release heat energy to the surroundings (temperature increases); endothermic reactions absorb heat (temperature decreases).
放热反应向环境释放热能（温度升高）；吸热反应吸收热能（温度降低）。
Bond breaking is endothermic, bond making is exothermic. ΔH = Σ(bond energies of bonds broken) − Σ(bond energies of bonds formed).
断裂化学键是吸热过程，形成化学键是放热过程。ΔH = 断裂键的键能总和 − 形成键的键能总和。
Enthalpy profile diagrams show energy changes. Activation energy (Eₐ) is the minimum energy needed for particles to collide successfully.
焓变示意图可显示能量变化。活化能 (Eₐ) 是粒子发生有效碰撞所需的最低能量。
7. Rates of Reaction | 反应速率
Rate of reaction can be followed by measuring the change in mass, volume of gas produced, or colour/ turbidity over time.
反应速率可通过测量质量变化、产生气体的体积或颜色/浑浊度随时间的变化来跟踪。
Factors affecting rate: concentration (increases collision frequency), temperature (increases energy and frequency), surface area (exposes more particles), and catalysts (provide an alternative pathway with lower activation energy).
影响速率的因素：浓度（增加碰撞频率）、温度（增加能量和频率）、表面积（暴露更多粒子）以及催化剂（提供活化能更低的替代路径）。
Collision theory: for a reaction to occur, particles must collide with sufficient energy (≥ Eₐ) and the correct orientation.
碰撞理论：反应发生要求粒子以足够的能量（≥ Eₐ）和正确的取向发生碰撞。
8. Organic Chemistry | 有机化学
A homologous series is a family of organic compounds with the same general formula, similar chemical properties, and a trend in physical properties.
同系物是一类具有相同通式、相似化学性质以及递变的物理性质的有机化合物。
Alkanes: general formula CₙH₂ₙ₊₂. They are saturated, unreactive, but combust in oxygen. Substitution with halogens requires UV light.
烷烃：通式为 CₙH₂ₙ₊₂。它们是饱和的，不活泼，但在氧气中可燃烧。与卤素的取代反应需要紫外光。
Alkenes: CₙH₂ₙ, contain a C=C double bond. They undergo addition reactions (e.g. with Br₂ water turning from orange to colourless, which is a test for unsaturation).
烯烃：CₙH₂ₙ，含有 C=C 双键。它们能发生加成反应（例如使溴水从橙色变为无色，这是检验不饱和键的方法）。
Alcohols, carboxylic acids, and esters are found in the syllabus; know their functional groups and typical reactions (combustion, oxidation, esterification).
教学大纲中还包含醇、羧酸和酯；需要掌握它们的官能团和典型反应（燃烧、氧化、酯化）。
9. Chemical Analysis | 化学分析
Flame tests: Li⁺ (red), Na⁺ (yellow), K⁺ (lilac), Ca²⁺ (orange‑red), Cu²⁺ (blue‑green). Clean the wire with concentrated HCl before use.
焰色反应：Li⁺（红色）、Na⁺（黄色）、K⁺（淡紫色）、Ca²⁺（橙红色）、Cu²⁺（蓝绿色）。使用前用浓盐酸清洁铂丝。
Cation tests: add NaOH(aq) to identify precipitates – e.g. Cu²⁺ forms a blue precipitate, Fe²⁺ forms green, Fe³⁺ forms brown. Some precipitates dissolve in excess NaOH (e.g. Zn²⁺, Al³⁺).
阳离子检验：加入 NaOH 溶液观察沉淀——例如 Cu²⁺ 产生蓝色沉淀，Fe²⁺ 产生绿色，Fe³⁺ 产生棕色。某些沉淀溶于过量 NaOH（如 Zn²⁺、Al³⁺）。
Anion tests: carbonates (add acid, produce CO₂, test with limewater), halides (add nitric acid then silver nitrate: Cl⁻ white, Br⁻ cream, I⁻ yellow), sulfates (add HCl then BaCl₂, white precipitate).
阴离子检验：碳酸根（加酸产生 CO₂，用石灰水检验）、卤离子（加硝酸酸化后加硝酸银：Cl⁻ 白色、Br⁻ 奶油色、I⁻ 黄色）、硫酸根（加盐酸酸化后加 BaCl₂，白色沉淀）。
10. Practical Skills & Formulae | 实验技能与常用公式
Familiarise yourself with titration procedures, making standard solutions, and using simple distillation, filtration, and chromatography.
熟悉滴定操作、配制标准溶液以及使用简单蒸馏、过滤和色谱法。
concentration (mol/dm³) = moles / volume (dm³)
浓度 (mol/dm³) = 物质的量 (mol) / 体积 (dm³)
percentage yield = (actual yield / theoretical yield) × 100
产率 = (实际产量 / 理论产量) × 100
Always record variables, repeat experiments, and identify anomalies. Accuracy, precision, and reliability are assessed differently.
始终记录变量、重复实验并识别异常值。准确性、精密度和可靠性需要分开评估。
Published by TutorHao | Chemistry Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
屏轩国际教育cambridge primary/secondary checkpoint, cat4, ukiset,ukcat,igcse,alevel,PAT,STEP,MAT, ibdp,ap,ssat,sat,sat2课程辅导，国外大学本科硕士研究生博士课程论文辅导Cancel reply