C2 - Investigate the reactivity of metals

• The reactivity of metals can be compared by timing how long each metal takes to react with acid; the fastest reaction indicates the most reactive metal.

• To ensure a fair test, each metal must be the same mass and form, and the same volume and concentration of acid must be used.

• The investigation becomes more reliable by repeating trials and averaging results, and can be made more precise by measuring gas volume with a gas syringe.

In this reaction you are going to add metals to acid and time how long the reaction takes to finish.

The reaction that finished the quickest is the one involving the most reactive metal.

• 250 cm³ beaker

• 100cm³ measuring cylinder

• 0.5g of each test metal - magnesium, zinc and iron

• Hydrochloric acid (300cm³)

• Stopwatch

1. Carefully measure 100 cm³ of hydrochloric acid using the measuring cylinder and place it in the beaker.

2. Add 0.5g of the first test metal – magnesium – to the acid in the beaker.

3. Start the stopwatch.

4. Record the time it takes for the gas to stop being produced and for the metal to disappear.

5. Repeat these steps for the other test metals – zinc and iron.

To make the investigation more reliable each metal could be tested again and an average of the two times calculated.

This investigation could also be carried out by timing how long the reaction takes to produce a certain volume of gas.

The gas could be collected in a gas syringe.

To make this investigation a fair test, the metal should be the same mass and in the same form, e.g. granules or powdered.