Chemistry paper 1 practicals

• Making salt crystals


  1. Heat concentrated acid in a beaker

  2. Add excess copper oxide

  3. Filter out unreacted copper oxide

  4. Gently heat the solution in an evaporating basin over a beaker of water on a tripod above a Bunsen burner flame

  5. Solid crystals of copper sulfate are left
• Electrolysis

  1. Put the solution (e.g. sodium chloride) in a beaker

  2. Get two carbon electrodes and put them in the solution making sure they don't touch

  3. Connect the electrodes to a power supply or battery, with the positive terminal (usually red) as the anode and the negative terminal (black) as the cathode

  4. Positive ions (cations) will be reduced at the cathode, negative ions (anions) will be oxidised at the anode
• Measuring rates of reaction

  1. If a gas is made, measure the volume of gas produced every 10 seconds and plot against time

  2. If a cloudy product is formed, time how long it takes for a cross drawn on paper below the flask to disappear when viewed from above
• Chromatography


  1. Put a spot of the mixture just above the bottom of chromatography paper

  2. Secure the paper so the bottom just touches distilled water in a test tube or beaker

  3. Wait for the water to move up the paper by capillary action, pulling the particles with it

  4. Calculate the Rf value (distance solute moved / distance water moved)
• Water purification


  Heat the water in a flask with a tube going through a condenser or to a beaker of ice, to distil the water and leave impurities behind
• Neutralisation titration


  1. Measure out a specific volume of alkali in a conical flask and add an indicator

  2. Fill a burette with the acid up to the 0 cm3 mark

  3. Slowly add the acid from the burette, swirling after each drop, until the indicator turns and stays pink

  4. Use the volume of acid needed and the known concentrations to calculate the unknown concentration
• Identifying ions


  1. Flame test for metal ions

  2. Add acid and barium chloride to test for carbonate, halide, and sulfate ions
• If the water is purified well in the water purification practical, you shouldn't see positive tests for sodium or chloride ions