Required practicles

• Titration

  1. Use a pipette to transfer 25cm³ of sodium hydroxide solution into a conical flask
  2. Add 5 drops of indicator to the alkali in the conical flask
  3. Place a conical flask on a white tile so we can see a colour change
  4. Fill a burette with sulphuric acid
  5. Add acid to the alkali until solution is neutral- add just enough
  6. Once there is a colour change add the acid drop by drop until solution is neutral- important to swirl the solution to make mix
  7. Read the volume of acid added from the burette- read at eye level and read at the bottom of the meniscus
  8. Repeat and take a mean
• Electrolysis of copper (ll) chloride solution

  1. Pour approximately 50cm³ of copper (ll) chloride solution into a beaker
  2. Insert 2 carbon graphite rods in the solution making sure they don't touch- if they touched it would produce a short circuit (these are the electrodes)
  3. Attach crocodile leads to the electrodes and the connect it to the terminals of a low voltage power supply
  4. Select 4V on the power supply and switch it on
• Observations of copper (ll) chloride solution electrolysis

  At the cathode:

  Coated with copper- copper less reactive than hydrogen so it is formed

  At the anode:

  Bubbles of gas and the smell of chlorine- chloride is a halide ion so hydrogen is discharged.

  If we hold a piece of damp litmus paper near the anode the it becomes bleached which proves the gas is chlorine
• Electrolysis of sodium chloride

  1. Place approximately 50cm³ of sodium chloride solution into a beaker
  2. Insert 2 carbon graphite rods in the solution making sure they don't touch- if they touched it would produce a short circuit (these are the electrodes)
  3. Attach crocodile leads to the electrodes and the connect it to the terminals of a low voltage power supply
  4. Select 4V on the power supply and switch it on
• Observations of electrolysis of sodium chloride

  At the anode:

  Bubbles of gas produced which bleaches damp blue litmus paper- which tells us this is chlorine (halide ion)

  At the cathode:

  Bubbles which is hydrogen gas - sodium is more reactive than hydrogen so hydrogen is produced

  To test for hydrogen- collect the gas and test it with a lit splint (hydrogen produces a squeaky pop sound)