Making Salts 2 - Science

Aim: To produce copper sulfate salt by reacting copper dioxide with an acid.

Equipment:

• Copper oxide powder
• Dilute (0.5 mol L-1)
• Sulfuric acid
• 50mL measuring cylinder
• 2 100mL beakers
• Hot plate
• Gauze mat
• Funnel
• Filter
• Paper 
• Thermometer
• Spatula
• Evaporating basin
• Stirring rod

Method: 

1. Add 20 mL of sulfuric acid to a 100 mL beaker. Heat the acid until it reaches 70°C. Turn off your bunsen burner (in our case the hot plate). 
2. Once heated, use a spatula to add pea-sized portions of copper oxide to the beaker. Stir the mixture for 30 seconds.
3. Repeat step 2 until no more will dissolve. Allow the beaker to cool. 
4. Fold the filter paper and place it in the funnel. Place the filter funnel into the second beaker. 
5. Make sure the beaker is cold enough to hold at the top. The contents should still be hot. You may need your teacher to complete this step. 
6. Gently swirl the contents of the beaker to mix, and then pour into the filter paper in the funnel. Allow to filter through. 
7. Rinse the beaker you used to heat the mixture previously, and place it back on top of your tripod filled with 50-60mL of water.
8. Place the evaporating basin on top of the beaker and carefully pour some of the solution from the beaker into the evaporating basin. 
9. Gently heat the beaker until the solution in the evaporating basin has reduced by half. 
10. Leave the evaporating basin to cool. Once cool, move the evaporating basin to a warm place where it will not be disturbed (i.e. a window-sill) and observe over the next few days. Blue copper sulfate crystals should form. 

Observations: As the mixture heated the colour changed. The mixture of sulfuric acid and copper oxide turned the mixture into a murky substance. The clear liquid-sulfuric acid-add copper oxide turned dark blue-filtered-lighter blue. 

Name of the reaction occurring in step 2: The reaction is called neutralisation.