Cambridge IGCSE · 分析与预测
2024 Cambridge IGCSE Chemistry (0620) 历年真题分析与预测
A balanced but rigorous Paper 4 (Extended) that tests key areas including stoichiometry calculation of hydrated zinc sulfate, transition metal properties, the Contact process equilibrium shifts, and organic polymer/cracking chemistry.
更新: 2026年6月13日
分析模拟试题
难度 3.8/5
总分
160
时间
180 分钟
最高频考点
—
分卷
卷二 選擇題 (Extended): 40 分 · 45 分钟Paper 4 Theory (Extended): 80 分 · 75 分钟Paper 6 Alternative to Practical: 40 分 · 60 分钟
考官重点
官方报告整理常见失分点
- Forgetting to balance chemical equations, especially for non-standard reactions like the decomposition of copper(II) nitrate.
- Omitting state symbols in ionic equations for precipitation reactions (e.g., Ba2+ and SO42- as (aq), BaSO4 as (s)).
- Incorrectly identifying the charge on ions in zinc/copper transitions, or writing incorrect symbols for transition metal ions.
- Omitting the single bond between oxygen and hydrogen (O-H) when drawing displayed formulae of alcohols.
常见误区
- Believing that a catalyst increases the yield of a product in a reversible reaction rather than just speeding up the rate of both forward and reverse reactions.
- Confusing sacrificial protection with barrier protection; candidates must explain that magnesium loses electrons more readily than iron, not just that it acts as a physical shield.
- Misinterpreting the term 'solution' as a pure liquid, or failing to identify the solute and solvent parts.
失分原因
- Truncating intermediate numbers in multi-step stoichiometry calculations, resulting in rounding errors for the final value of x.
- Providing imprecise definitions of electrolysis, such as failing to specify that the ionic compound must be molten or in aqueous solution.
- Inability to construct correct ionic half-equations at the anode, specifically the oxidation of hydroxide ions to form oxygen and water.
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