Instrumental analysis and flame tests: including barium
Lesson details
Learning outcome
I can identify metal ions based on the colour of their flame tests and understand how instrumental analysis methods are used for detecting and identifying elements.
Key learning points
- Positive ions burn with distinct colours that are visible when heated above a blue Bunsen flame.
- Instrumental methods are accurate, sensitive, and rapid for detecting and identifying elements and compounds.
- Unique flame emission spectra are produced for each positive metal ion.
- A spectrometer can split light from coloured flames into flame emission spectra.
- A spectrometer can measure more than one metal ion in a single solution and the concentration of each.
Keywords
Flame test - A test where a chemical put into a flame produces a characteristic colour (tests for metal ions).
Spectroscope - An instrument that separates light into its component wavelengths.
Ion - An ion is an atom or group of atoms with a positive or negative charge due to the loss or gain of electrons.
Concentration - The amount of a solute dissolved in a certain volume of solvent.
Calibration curve - A graph used to determine the concentration of a substance in a sample.
Common misconception
Flame colours are unique, even in mixtures.
Explain that strong colours, like sodium's yellow, can mask others. Use spectrometry to identify masked elements.
Teacher tip
Ensure safety precautions are followed; use clean equipment to avoid contamination during flame tests.
Equipment
Bunsen burner setup, 'unknown' metal salt samples to do flame tests, nichrome wire loops, dilute hydrochloric acid, beakers, matches.
Content guidance
Risk assessment required - chemicals
Risk assessment required - equipment
Supervision
Adult supervision required
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which of the following particles are not found in the nucleus of an atom?
Q2.What charge does an ion have if it has gained electrons?
Q3.Which part of the atom is involved in chemical bonding?
Q4.Which of the following is a general property of metals?
Q5.Where are metals generally located on the periodic table?
Q6.What is an ion?
Assessment exit quiz
6 Questions
Q1.What is the purpose of a flame test?
Q2.What flame colour does potassium produce?
Q3.Why is it important to clean the wire loop before conducting a flame test?
Q4.What happens to electrons in metal ions when they absorb energy from the flame?
Q5.Why do different metal ions produce different flame colours?
Q6.What is emitted when electrons in metal ions return to their ground state after excitation?
To help you plan your 11 chemistry lesson on: Instrumental analysis and flame tests: including barium, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 11 chemistry lesson on: Instrumental analysis and flame tests: including barium, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 4 chemistry lessons from the Chemical analysis unit, dive into the full secondary chemistry curriculum, or learn more about lesson planning.