| Method |
Precise Learning Objective |
Linked |
Question / Activity
(Designed for maximum working out) |
Stepping Stones |
Pitstop Check
(Thinking Map) |
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Required practical 7 - identifying ions (AT skills 1,8) |
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Use of chemical tests to identify the ions in unknown single ionic compounds
covering the ions from Flame tests and sulphates. |
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Sulfate ions in solution produce a white precipitate with barium chloride solution in the presence of dilute hydrochloric acid. |
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What do Sulfate ions in solution produce when they react with barium chloride in the presence of hydrochloric acid? |
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Sodium hydroxide solution can be used to identify some metal ions (cations). |
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What solution can be used to identify some some metal ions (cations)? |
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Solutions of aluminium, calcium and magnesium ions form white precipitates when sodium hydroxide solution is added but only the aluminium hydroxide precipitate dissolves in excess sodium hydroxide solution.
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What do solutions of aluminium, calcium and magnesium ions form? |
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Solutions of copper(II), iron(II) and iron(III) ions form coloured precipitates when sodium hydroxide solution is added. Copper(II) forms a blue precipitate, iron(II) a green precipitate and iron(III) a brown precipitate.
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What happens when sodium hydroxide is added to Solutions of copper(II), iron(II) and iron(III) ions? |
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Students should be able to write balanced equations for the reactions to produce the insoluble hydroxides. |
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Write a balanced equation for reactions that produce the insoluble hydroxides. |
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Students are not expected to write equations for the production of sodium aluminate. |
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Flame emission spectroscopy is an example of an instrumental method used to analyse metal ions in solutions. |
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What is Flame emission spectroscopy used for? GCSE pod video on flame emission spectroscopy brilliantly explains the process. Link back to why it is a more reliable test than a basic flame test. |
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The sample is put into a flame and the light given out is passed through a spectroscope. The output is a line spectrum that can be analysed to identify the metal ions in the solution and measure their concentrations. |
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What can the output of a line spectrum be used for? |
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Students should be able to interpret an instrumental result given appropriate data in chart or tabular form, when accompanied by a reference set in the same form, limited to flame emission spectroscopy. |
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