Use
approximately 0.5M copper sulphate solution for the following reactions.
1.
Place
about 1-2 cm3 of the copper sulphate solution in a test-tube.
Observe the colour of the solution.
What copper (II) ion is present in this solution?
|
Colour
of solution |
|
|
Formula
of ion |
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2. Add concentrated hydrochloric acid (CAUTION** CORROSIVE**) to the solution from part (1) a drop at a time to an excess.
Observe the colour of the solution.
What copper species is now present in the solution?
|
Colour
of solution |
|
|
Formula
of copper complex |
|
3.
Dilute
the solution from part (2) with five to ten times its own volume of water.
Comment on your observations.
|
Observations
and equations |
|
4.
Treat
1-2 cm3 of the copper sulphate solution with concentrated ammonia solution added a drop at a time to
excess.
|
Observations
and equations |
|
1.
What
are the coordination numbers of the copper species present in water and in
concentrated hydrochloric acid?
2.
Write
one ionic equation summarising the reaction of copper sulphate with
concentrated hydrochloric acid and the effect of dilution.
3. Write an ionic equation for the reaction of copper sulphate solution with excess ammonia.
Cobalt
In each of the following experiments use about 1-2 cm3 of cobalt chloride solution (approx. 1.0M).
1. Observe the colour of the solution. What species is present in the water?
|
Colour
of solution |
|
|
Formula
of complex ion |
|
2. Add concentrated hydrochloric acid slowly until in excess. Dilute the solution with water.
Write an equation to describe the reactions occurring.
|
Observations and equations |
|
3. Add a few drops of dilute ammonia solution. Describe and give a formula for the precipitate.
|
Observation |
|
|
Formula of precipitate |
|
4 Add concentrated ammonia solution to an excess.
Observe carefully, especially at the top of the test-tube where the solution is in contact with the air.
|
Observations and equations |
|