Science at key stage 3 (Year 9)
Unit 9F: Patterns of reactivity
Section 3: Is the order of reactivity of metals with water the same as that with acids?
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Objectives |
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- that some metals react more readily with acids than others
- to decide which observations are relevant to a piece of work
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Activities |
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Outcomes |
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Children: |
- Remind pupils of work they did in unit 9E 'Reactions of metals and metal compounds' on the reactions of acids with metals and ask them what is formed. Help them to write word equations. Ask pupils to carry out quick reactions between either sulphuric acid or hydrochloric acid and filings of coarse metal mesh,
eg copper, iron, zinc, magnesium, and from their observations decide the order of reactivity. Ask them which observations they took account of, to compare the reactions of hydrochloric and sulphuric acid, and then to agree an order of reactivity. Compare this with what was established in the previous activity.
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- identify relevant observations,
eg extent of bubbling, rise in temperature
- use observations to suggest an order of reactivity
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Points to note |
- This activity is intended to be done quickly. There is an opportunity to investigate the reaction of some metals with acid later in the unit.
- At this point it is sufficient to ensure that similar amounts of each metal and similar amounts of acid are used. After the activity, pupils could be asked to evaluate how confident they are in their results and to consider which variables to control.
- Extension: pupils could be asked to write the symbols and formulae for reactants and products, and from these write symbol equations.
Safety
- 0.4 mol dm-3 acid should be used. Eye protection should be worn. Hydrogen sulphide (toxic) may be formed in the reaction with iron. However, this is not usually a safety problem. Supervise the use of magnesium. Coarse-mesh magnesium is highly flammable
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This unit is divided into sections. Each section contains a sequence of
activities with related objectives and outcomes. You can view this unit by
moving through the sections or print/download the whole unit.
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