Which metal is most reactive?
Put magnesium, zinc, iron and copper in dilute acid and compare the fizzing, then see which metals can push copper and zinc out of their salt solutions.
Core concept
Metals can be arranged in order of reactivity; a more reactive metal displaces a less reactive one
Topic: Metals and non-metals
Some metals react quickly, others slowly, and some hardly at all. Putting metals in dilute acid: A substance that tastes sour, like lemon juice or vinegar. It turns blue litmus red. All key words shows this clearly: the faster the metal fizzes (giving off hydrogen), the more reactive it is. Listing metals from most to least reactive gives the reactivity series. A more reactive metal can also push a less reactive metal out of its salt solution: A mixture where one substance has dissolved completely in a liquid, like salt water. All key words. This is called a displacement reaction.
What you will learn
- Compare the reactions of magnesium, zinc, iron and copper with dilute acid.
- Arrange the metals in a reactivity series.
- Predict and explain displacement reactions using the reactivity series.
Before you start
- Know that acids react with metals to give hydrogen. Try "Testing the properties of acids and bases" first.
Materials
- Magnesium ribbon, zinc granules, iron filings and copper turnings
- Dilute hydrochloric acid
- Copper sulfate solution and zinc sulfate solution
Equipment
- 6 test tubes in a rack
Procedure
- Tubes A–D contain dilute hydrochloric acid. Add a different metal to each and compare the fizzing.
- Tube E contains blue copper sulfate solution. Add iron filings and wait.
- Tube F contains zinc sulfate solution. Add copper turnings and wait.
- Use your results to put the four metals in order of reactivity.
How this simulation is simplified
- Reaction speeds are shown on a simple scale. Real rates depend on the size of the metal pieces and the acid strength.
- Displacement is shortened to a few minutes.