This exam tips covers Exam Tips for Ion Tests within Tests for Ions for GCSE Chemistry. Revise Tests for Ions in Chemical Analysis for GCSE Chemistry with 20 exam-style questions and 14 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 13 of 14 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
Topic position
Section 13 of 14
Practice
20 questions
Recall
14 flashcards
💡 Exam Tips for Ion Tests
🎯 Common Question Types:
- Identify ions from given test results (1 mark each)
- Describe tests to confirm presence of named ions (2–3 marks)
- Explain why acid must be added before BaCl₂ or AgNO₃ (2 marks)
- Write ionic equations for precipitation reactions (2 marks)
- Distinguish between similar ions (e.g. Al³⁺ vs Ca²⁺) (2 marks)
📝 Key Command Words:
- Describe: State reagent added AND expected observation
- Identify: Name the ion from given observations
- Explain: Give the chemical reason (e.g. why acid is added)
- Write the ionic equation: Include state symbols (aq), (s)
⚠️ Common Mistakes to Avoid:
- Forgetting acid in BaCl₂ and AgNO₃ tests — always acidify first
- Confusing Fe²⁺ (green) and Fe³⁺ (brown) — green = iron II, brown = iron III
- Saying "white precipitate" for Al³⁺ without mentioning it redissolves in excess
- Mixing up silver halide colours — white (Cl⁻), cream (Br⁻), yellow (I⁻)
- Not giving state symbols in ionic equations