AQA International A-level Chemistry CH04 Unit 4: Example Responses and Examiner Tips | AQA国际A-level化学第四单元(CH04)：范例答案与考官建议

📚 AQA International A-level Chemistry CH04 Unit 4: Example Responses and Examiner Tips | AQA国际A-level化学第四单元(CH04)：范例答案与考官建议

Welcome to this CH04 Unit 4 revision guide for AQA International A-level Chemistry. It brings together sample questions, model responses and examiner comments on kinetics, equilibria, acids and further organic chemistry. Use it to sharpen your exam technique and understand exactly what AQA examiners expect.

欢迎使用 AQA 国际 A-level 化学第四单元 (CH04) 复习指南。本文汇总了动力学、平衡、酸碱以及进一步有机化学的样题、范例答案和考官点评，帮助你打磨答题技巧，准确理解 AQA 考官的要求。

1. Unit 4 Overview and Assessment Demands | 第四单元概览与考查要求

CH04 covers four broad areas: kinetics, gas and solution equilibria, acid-base chemistry, and further organic reactions. Questions often combine calculation with explanation, so a model answer must show both the numerical method and the chemical reasoning.

CH04 涵盖四大板块：动力学、气相与溶液平衡、酸碱化学以及进一步的有机反应。题目常把计算与解释结合起来，因此范例答案必须既展示数值方法，也展示化学推理。

In the written paper, you can expect data-response questions on rate equations, Kc and Kp, buffers, and organic routes. Mark schemes reward correct units, significant figures, and phrases such as ‘equilibrium shifts to oppose the change’ rather than vague statements.

笔试中会出现关于速率方程、Kc 和 Kp、缓冲溶液以及有机合成路线的数据分析题。评分标准看重单位正确、有效数字正确，以及“平衡向抵消变化的方向移动”等准确表述，而不是含糊的描述。

2. Determining Reaction Orders from Initial Rates | 用初始速率法确定反应级数

Sample question: The table shows initial rate data for the reaction A + B → C. Deduce the order with respect to A and B, and write the rate equation.

样题：下表给出了反应 A + B → C 的初始速率数据。推断对 A 和 B 的反应级数，并写出速率方程。

Model response: Comparing runs 1 and 2, [A] doubles while [B] is constant; the rate increases by a factor of 4, so the order with respect to A is 2. Comparing runs 1 and 3, [B] triples while [A] is constant; the rate triples, so the order with respect to B is 1.

范例答案：比较实验 1 和 2，[A] 加倍而 [B] 不变；速率增大到 4 倍，所以对 A 的级数为 2。比较实验 1 和 3，[B] 增大到 3 倍而 [A] 不变；速率增大到 3 倍，所以对 B 的级数为 1。

Therefore the rate equation is:

因此速率方程为：

rate = k[A]²[B]

The units of k are mol⁻² dm⁶ s⁻¹.

k 的单位为 mol⁻² dm⁶ s⁻¹。

Common error: using the stoichiometric coefficients as orders. AQA expects you to show the comparison of

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