P1 Chemistry required practical

• Describe a test for temperature changes

  1. Use a measuring cylinder to measure 30cm3 of dilute hydrochloric acid and transfer the acid into a polystyrene cup

  2. Stand the polystyrene cup inside a beaker to prevent it from falling over

  3. Use a thermometer to measure the temperature of the acid and record this in a table

  4. Use a measuring cylinder to measure 5 cm3 of sodium hydroxide solution and transfer this to the polystyrene cup

  5. Fit a plastic lid to the cup and place the thermometer through the hole in the lid and gently stir the solution with the thermometer

  6. Record the highest temperature when the reading of the thermometer stops changing

  7. Rinse and dry the cup and repeat the whole experiment using 10 cm3 of sodium hydroxide solution

  8. Carry out the experiment several more times, each time increasing the volume of sodium hydroxide by 5cm3 until we reach a maximum of 40cm3 of sodium hydroxide solution

  9. Plot a graph of the results
• The reaction releases energy


  It is exothermic so the temperature of the solution will increase
• The test involves measuring temperature changes
• Describe a test for electrolysis

  1. Pour approximately 50 cm3 of copper (II) chloride solution into a beaker

  2. Place a petri dish over the beaker, the petri dish should have two holes to insert two electrodes

  3. The electrode must not touch each other as it will produce a short circuit

  4. Attach a crocodile clip/ leads to the rods and then connect them to a a low voltage power supply

  5. Select 4V on the power supply and switch it on

  6. Observe the electrodes

  7. Cathode is being coated with copper, copper is less reactive than hydrogen so it gets discharged at the cathode

  8. At anode, chlorine gas will be produced as chlorine ion is a halide ion so it gets oxidised to become chlorine atoms

  9. To test that chlorine is present, place a damp litmus paper near anode, the paper should become bleached

  10. 10. Repeat test with sodium chloride solution, squeaky pop nose will be created if hydrogen is produced at cathode
• describe a test for making copper sulfate crystals

  1. place some sulfuric acid in a conical flask and warm it in a water bath
  2. add a spatula of copper oxide powder to the acid and stir with a glass rod
  3. continue adding copper oxide powder until it is in excess
  4. filter the mixture to remove the excess copper oxide
  5. pour the filtrate (the copper sulfate solution) into an evaporating basin
  6. heat the copper sulfate solution to evaporate half of the water
  7. pour the solution into a watch glass and leave to allow all of the water to evaporate
• Titration test

  A test to determine the concentration of an unknown solution
• Titration procedure

  1. Use a pipette and pipette filler to add 25 cm3 of alkali solution or unknown to a clean conical flask

  2. Add a few drops of phenolphthalein indicator and put the conical flask on a white tile (indicator should not be over 5 drops as it is acidic and may disrupt the results)

  3. Rinse the burette with distilled water, fill the burette with dilute acid or known solution at eye level using a funnel, flush the tap through to remove any air bubbles, read the initial reading from the burette

  4. Slowly add the acid from the burette to the conical flask, swirling to mix (the mixture may at first change colour, and then back again when swirled)

  5. Stop adding the acid when the end-point is reached (when the colour first permanently changes from pink to colourless), note the final volume reading

  6. Repeat steps 1 to 5 until three results are repeatable (ideally these should lie within 0.10 cm3 of each other, concordant)