📚 AQA 9620 CH05 International A-level Chemistry Specimen Paper 2016: Mastering Thermodynamics, Equilibria and Organic Analysis | AQA 9620 CH05 国际A-level化学2016样卷：攻克热力学、平衡与有机分析
The AQA 9620 CH05 International A-level Chemistry specimen paper is a demanding assessment that tests second-year physical, inorganic and organic chemistry in a single paper. Students often find it challenging because it mixes quantitative calculations, recall of reaction conditions, and interpretation of unfamiliar data. This article breaks down the main topic areas, highlights common traps, and gives you a structured revision plan so you can approach the specimen paper with confidence.
AQA 9620 CH05 国际A-level化学样卷是一份要求很高的试卷，在一张卷子里考查第二学年的物理化学、无机化学和有机化学。学生常觉得困难，因为它混合了定量计算、反应条件的记忆以及对陌生数据的解读。本文拆解主要知识板块，指出常见陷阱，并给你一套结构化复习方案，让你自信应对样卷。
1. Overview of the CH05 Specimen Paper | 单元5样卷概览
CH05 is usually taken in the second year of the International A-level. The 2016 specimen paper includes a range of question styles: structured short answers, calculations, graph interpretation, and extended responses. Marks are spread across Assessment Objectives AO1 (recall), AO2 (application) and AO3 (analysis and evaluation), so you need more than memorisation.
CH05 通常在国际A-level第二学年学习。2016年样卷包含多种题型：结构化简答、计算、图像解读和扩展作答。分数分布在 AO1（记忆）、AO2（应用）和 AO3（分析与评价），因此你需要的不仅是背诵。
Below is a typical topic map for the paper. Use it to identify your weak areas before attempting the specimen under timed conditions.
下面是该样卷的典型知识板块分布。在计时模拟样卷之前，用它来找出你的薄弱环节。
| Topic Area | Knowledge Area | Typical Task |
|---|---|---|
| Thermodynamics | 热力学 | Born-Haber cycles, entropy, Gibbs free energy |
| Equilibrium | 化学平衡 | Kc, Kp, ICE tables, buffers |
| Electrochemistry | 电化学 | E°cell, oxidising/reducing agents |
| Transition Metals | 过渡金属 | Complexes, colour, isomerism |
| Organic Chemistry | 有机化学 | Synthesis, mechanisms, carbonyls |
| Spectroscopy | 光谱学 | IR, MS, ¹H NMR, ¹³C NMR |
2. Thermodynamics: Born-Haber Cycles and Entropy | 热力学：玻恩-哈伯循环与熵
You must be able to construct Born-Haber cycles for ionic compounds such as NaCl, MgO and CaF₂. The key enthalpy definitions are lattice enthalpy, enthalpy of atomisation, ionisation energy, electron affinity and enthalpy of formation. Remember that electron affinity is usually exothermic, but the second electron affinity of oxygen is endothermic.
你必须会构建 NaCl、MgO 和 CaF₂ 等离子化合物的玻恩-哈伯循环。关键焓定义包括晶格焓、原子化焓、电离能、电子亲和能和生成焓。记住电子亲和能通常放热，但氧的第二电子亲和能是吸热的。
ΔH꜀(formation) = ΔHₐₜ(atomisation) + ΣIE + ΣEA + ΔHₗₐₜₜᵢ꜀ₑ
A common exam task is to calculate an unknown lattice enthalpy from a cycle, or to explain why theoretical and experimental lattice enthalpies differ for a compound such as AgCl. Differences suggest covalent character.
常见考题是计算循环中的未知晶格焓，或解释 AgCl 等化合物理论晶格焓与实验值不同的原因。差异表明存在共价特性。
Entropy, S, measures the dispersal of energy. Gases have higher entropy than liquids, which have higher entropy than solids. A reaction in which the number of gas molecules increases usually has a positive ΔS.
熵 S 衡量能量的分散程度。气体的熵高于液体，液体的熵高于固体。气体分子数增加的反应通常 ΔS 为正。
3. Gibbs Free Energy and Feasibility | 吉布斯自由能与反应可行性
calculate the minimum temperature at which a reaction becomes feasible by setting ΔG = 0.
在一定温度下判断反应是否可行使用 ΔG = ΔH − TΔS。ΔG 为负表示反应热力学可行。你可能需要通过令 ΔG = 0 计算反应变得可行的最低温度。
ΔG = ΔH − TΔS
+400 J K⁻¹ mol⁻¹, the minimum temperature is T = 120000 J mol⁻¹ / 400 J K⁻¹ mol⁻¹ = 300 K.
注意单位：ΔH 常以 kJ mol⁻¹ 给出，而 ΔS 以 J K⁻¹ mol⁻¹ 给出。相除前要把 kJ 换算成 J。例如，若 ΔH = +120 kJ mol⁻¹，ΔS = +400 J K⁻¹ mol⁻¹，则最低温度 T = 120000 J mol⁻¹ / 400 J K⁻¹ mol⁻¹ = 300 K。
Feasibility is not the same as rate. A reaction may have a negative ΔG but be extremely slow because of a high activation energy. Exam questions often ask you to explain why a feasible reaction does not occur at room temperature.
可行性与速率不是一回事。反应可能 ΔG 为负，但由于活化能很高而极其缓慢。考试常要求你解释为什么一个可行的反应在室温下并未发生。
4. Electrode Potentials and Electrochemical Cells | 电极电势与电化学电池
ore positive reduction potential as the cathode. A positive E°cell indicates a feasible reaction under standard conditions.
你需要组合半电池计算标准电动势：E°cell = E°cathode − E°anode，以还原电位较正的一侧为阴极。E°cell 为正表示反应在标准条件下可行。
E°cell = E°cathode − E°anode
Questions often present a table of standard electrode potentials and ask you to identify the strongest oxidising agent or to predict whether a reaction will occur. Remember that feasibility may change under non-standard conditions.
题目常给出标准电极电势表，要求你找出最强的氧化剂或预测反应是否发生。记住，非标准条件下可行性可能改变。
- electrode uses H₂ gas at 100 kPa, 298 K, and [H⁺] = 1 mol dm⁻³ with a platinum electrode.
- 标准氢电极使用 H₂ 气体、100 kPa、298 K、[H⁺] = 1 mol dm⁻³，以铂为电极。
- The more positive E° value means the species is more easily reduced, so it is the stronger oxidising agent.
- E° 值越正，物种越容易被还原，因而是更强的氧化剂。
- In a cell diagram, the half-cell with the more negative E° is placed on the left and supplies electrons to the external circuit.
- 在电池图示中，E° 较负的半电池写在左侧，向外部电路提供电子。
5. Acids, Bases and Buffer Solutions | 酸、碱与缓冲溶液
s and bases use concentration directly; for weak acids use Ka and the approximation [H⁺] = √Ka × [HA].
pH 计算是核心。强酸强碱直接用浓度；弱酸使用 Ka，近似 [H⁺] = √Ka × [HA]。
pH = −log₁₀[H⁺]
Kw = [H⁺][OH⁻] = 1.0 × 10⁻¹⁴ mol² dm⁻⁶ at 298 K
are made from a weak acid and its conjugate base. The key equation is Ka = [H⁺][A⁻]/[HA].
缓冲溶液在加入少量酸或碱时能抵抗 pH 变化。它由弱酸及其共轭碱组成。关键方程是 Ka = [H⁺][A⁻]/[HA]。
pH = pKa + log₁₀([A⁻]/[HA])
Titration curves for strong acid–strong base, strong acid–weak base, weak acid–strong base and weak acid–weak base are frequently tested. Know the pH at equivalence point and suitable indicators.
强酸-强碱、强酸-弱碱、弱酸-强碱和弱酸-弱碱的滴定曲线常考。要知道滴定终点 pH 和合适的指示剂。
| Titration Type | Titration Type | pH at Equivalence Point | Suitable Indicator |
|---|---|---|---|
| Strong acid – strong base | 强酸 – 强碱 | 广告 / Sponsored 英国CGP原版 A-Level Chemistry: AQA Year 1 & 2 Complete Revision… 化学 备考教辅 · 正版现货 · 与本文内容相关 查看详情 / View on Taobao参考价 ¥292.0
更多咨询请联系16621398022（同微信） 备考资讯每日更新，关注不错过 考纲变化 · 科目分析 · 学习方法  在微信里长按二维码识别关注 或截图后用「扫一扫 → 相册」选择本图 公众号：tutorhao |