CChemistryS3 to S6Qualitative analysis

Salt analysis lab: identify the unknown salts

A school store has seven jars that lost their labels. Do the tests a chemist would do, record what you see, and name every salt.

▶ Start the lab 🧠 Questions 📄 My report

LevelS3 to S6 (and IGCSE, A Level)

TimeAbout 45 min

You useFlame tests, precipitates, gas tests

PriceFree: no account

🎯 Aim

To identify the cation and the anion in unknown salts using flame tests, precipitation with sodium hydroxide and aqueous ammonia, and tests for carbonate, chloride and sulfate ions.

You will learn to

Carry out and record qualitative tests in order.
Use precipitate colours and solubility in excess to identify cations.
Use gas and precipitate tests to identify anions.
Write ionic equations for precipitation reactions.

🧭 What to do

Choose Salt A and the Flame test. Tap Do the test.
Do every test on Salt A: your observations fill the results table.
Use your observations to choose the Cation and the Anion, then tap Check my identification.
Repeat for Salts B to G.
Answer the questions.
Write your conclusion and download your lab report.

🔬 Lab bench

📋 The data

Observations from the tests on seven unknown salts.

🧠 Investigate: answer from the data

Type your answer and tap Check. Use 💡 Hint first; open the method only when you are stuck.

📄 My lab report

Your report collects the aim, your data table, the graphs, your answers and your conclusion. It is made on your phone or computer: nothing is sent to anyone.

My conclusion

Check your conclusion

Each cation gives a typical result: Cu²⁺ a blue precipitate that dissolves in excess ammonia to a deep blue solution; Fe²⁺ green and Fe³⁺ red-brown precipitates; Zn²⁺ a white precipitate soluble in excess; Ca²⁺ a white precipitate with NaOH and a brick-red flame; Na⁺ a yellow-orange flame; NH₄⁺ ammonia gas on warming with NaOH. Anions: carbonate fizzes with acid giving CO₂; chloride gives a white precipitate with acidified silver nitrate; sulfate a white precipitate with acidified barium chloride.

➕ Get more from this experiment

📝 Free

Print the worksheet (button above), download the data, and save your report. Teachers can project this page in class.

📦 Premium Lab Pack

1 000 RWF

Practical worksheet for real salt analysis in the school lab
Table of tests and observations to learn
Teacher guide, safety notes and answer key
Exam-style qualitative analysis questions with marking scheme

See the pack

👩‍🏫 For teachers

Use it as a practical when apparatus is missing, as homework, or as a project. Free lesson plans help you plan, teach and assess.

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