AQA A Level Chemistry June 2018 Insert 5: Organic Analysis Data Skills | AQA A Level 化学 2018年6月 Insert 5:有机分析数据技能

📚 AQA A Level Chemistry June 2018 Insert 5: Organic Analysis Data Skills | AQA A Level 化学 2018年6月 Insert 5:有机分析数据技能

In AQA A Level Chemistry, the June 2018 Insert 5 is a data sheet used for organic analysis questions. It typically gives infrared absorption ranges, proton and carbon-13 NMR chemical shift data, and common mass spectrometry fragment ions. This article explains how to use Insert 5 accurately, avoid common errors, and link spectroscopic evidence to an organic structure.

在 AQA A Level 化学中,2018年6月 Insert 5 是用于有机分析题的数据表。它通常提供红外吸收范围、质子与碳-13 核磁共振化学位移数据,以及常见的质谱碎片离子。本文讲解如何准确使用 Insert 5,避免常见错误,并将光谱证据与有机结构联系起来。

1. The Role of Insert 5 in the Examination | Insert 5 在考试中的作用

Insert 5 is not part of the question itself; it is a reference insert provided alongside the A level Chemistry paper. You are expected to locate the correct data block, quote values, and use them to justify a functional group or structural fragment. Marks are often awarded for explicitly linking a peak or shift to a part of the molecule.

Insert 5 不是试题本身,而是随 A Level 化学试卷提供的数据插页。你需要找到正确的数据块、引用数值,并用它们证明官能团或结构片段的存在。题目通常会给分,只要你明确将峰的波数或化学位移与分子中的某部分联系起来。

In the June 2018 series, Insert 5 was especially relevant to organic structure determination questions. The insert is usually divided into IR, ¹H NMR, ¹³C NMR, and mass spectrometry tables. When a question says “Use the data in Insert 5”, you must refer to the insert and cite specific values rather than guessing from memory.

在 2018 年 6 月的考试系列中,Insert 5 对有机结构推断题尤其重要。该插页通常分为红外、¹H NMR、¹³C NMR 和质谱表格。当题目要求“使用 Insert 5 中的数据”时,你必须引用插页中的具体数值,而不是仅凭记忆猜测。


2. Overview of the Data Provided in Insert 5 | Insert 5 数据概览

The insert normally contains four key types of data: IR absorption bands in wavenumbers cm⁻¹, ¹H NMR chemical shifts in ppm, ¹³C NMR chemical shifts in ppm, and mass spectrometry fragment ions as m/z ratios. Knowing how to navigate these tables saves time under exam pressure.

该插页通常包含四种关键数据:以波数 cm⁻¹ 表示的红外吸收峰、以 ppm 表示的 ¹H NMR 化学位移、以 ppm 表示的 ¹³C NMR 化学位移,以及以 m/z 表示的质谱碎片离子。熟悉这些表格可以节省考试时间。

Data type Typical examples in Insert 5 Used to identify 中文说明
Infrared C=O 1680–1750 cm⁻¹, O–H 3200–3550 cm⁻¹ Functional groups such as carbonyl and hydroxyl 识别羰基、羟基等官能团
¹H NMR RCH₃ 0.7–1.2 ppm, RCHO 9.5–10.0 ppm Proton environments and neighbouring protons 质子环境与相邻质子
¹³C NMR C=O 190–220 ppm, C–O 50–70 ppm Number of non-equivalent carbon environments 非等性碳环境的数量
Mass spectrometry CH₃⁺ 15, C₂H₅⁺ 29, C₆H₅⁺ 77 Fragments that reveal alkyl or aryl groups 揭示烷基或芳基的碎片

Always check the exact ranges in Insert 5 because AQA data booklets may differ slightly from other exam boards. The values printed in the insert must be used in your answer if the question asks for justification.

务必检查 Insert 5 中给出的精确范围,因为 AQA 的数据表可能与其他考试局略有不同。如果题目要求用数据证明,就必须使用插页中印出的数值。


3. Infrared Data: Identifying Functional Groups | 红外数据:识别官能团

IR absorption in Insert 5 is reported as a range in wavenumbers, cm⁻¹. A strong, sharp peak near 1680–1750 cm⁻¹ is the most reliable evidence for a C=O carbonyl group. The exact position within that range can suggest whether the carbonyl is an aldehyde, ketone, ester, carboxylic acid, or amide.

Insert 5 中的红外吸收以波数 cm⁻¹ 的范围表示。在 1680–1750 cm⁻¹ 附近出现的强而尖锐的吸收峰,是 C=O 羰基最可靠的证据。该范围内的具体位置可以提示羰基是醛、酮、酯、羧酸还是酰胺。

A broad O–H stretch in alcohols usually appears around 3200–3550 cm⁻¹, while the O–H of a carboxylic acid is often very broad and centred in the 2500–3000 cm⁻¹ region. The acid O–H band is sometimes broad enough to overlap with the C–H stretch, so you should look for the C=O band as well.

醇中的宽 O–H 伸缩振动通常出现在约 3200–3550 cm⁻¹,而羧酸的 O–H 通常非常宽,集中在 2500–3000 cm⁻¹ 区域。羧酸的 O–H 峰有时宽到会与 C–H 伸缩振动重叠,因此还应同时寻找 C=O 峰。

N–H stretches in amines and amides are found around 3300–3500 cm⁻¹. They are usually broader and weaker than O–H, so interpretation can be tricky. C=C stretches are seen around 1620–1680 cm⁻¹ and are useful when combined with other evidence.

胺和酰胺中的 N–H 伸缩振动出现在约 3300–3500 cm⁻¹。它们通常比 O–H 峰更宽、更弱,因此解释起来可能比较困难。C=C 伸缩振动出现在约 1620–1680 cm⁻¹,在结合其他证据时很有用。

Bond Typical range / cm⁻¹ Observation in spectrum 中文注释
C–H 2850–3300 Sharp to medium, present in most organics 多数有机物中可见
O–H alcohol 3200–3550 Broad and strong 宽而强
O–H acid 2500–3000 Very broad, often overlaps C–H 非常宽,常与 C–H 重叠
N–H 3300–3500 Broad, weaker than O–H 宽而弱于 O–H
C=O 1680–1750 Strong and sharp 强而尖锐
C=C 1620–1680 Medium to weak, variable 中等偏弱,变化较大

When using IR data, avoid claiming that a single C=O peak tells you the exact molecule. It tells you a carbonyl is present. You must combine it with NMR and mass spectrometry to distinguish an ester from a carboxylic acid, ketone, or aldehyde.

使用红外数据时

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