Specified practical - metal displacement reactions

Displacement in solutions

There are a number of ways that you could investigate a displacement reaction. This is an outline of the required steps to undertake one of these methods.

Aims

To investigate displacement reactions and produce a reactivity series for metals.

Method

  1. use a dropping pipette to place some zinc sulfate solution in one row of a dimple tray
  2. use clean dropping pipettes to fill the other rows of the dimple tray with magnesium sulfate solution, copper(II) sulfate solution and silver nitrate solution
  3. place a piece of zinc metal in each dimple in the solutions in the first column of the dimple tray
  4. place pieces of magnesium and copper in the other columns of the dimple tray
  5. observe and record the changes in the solutions or metal samples
A dimple tray with different substances in the dimples labelled.Reacting metals with metal salt solutions

Results

  1. describe any changes in the colour of the metal or the metal salt solution
  2. put the results in a table

Analysis

  1. use the results to construct a reactivity series for the metals used
  2. write equations for any reactions that occurred

Evaluation

Question

Some students did not test combinations of the same metal, such as magnesium and magnesium sulfate solution. Suggest why.

A metal cannot displace itself, so no reaction would take place.

Question

Which metal is the most reactive?

Magnesium is the most reactive metal because a displacement reaction takes place with all the salt solutions.

Hazards, risks and precautions

It is important in this practical activity to use appropriate apparatus and methods. This includes the safe use and careful handling of substances.

Evaluate the hazards and the precautions needed to reduce the risk of harm. For example:

HazardHarmPrecaution
Salt solutionsIrritate the eyesWear eye protection
Salt solutionsMetal ions absorbed through the skinCarefully wipe up spills and wash hands
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