Topics to revise
Chemical Change P1
Organisation - Transport P1
Required practical - Electrolysis
Required practical - Prepare a pure dry salt
Electrolysis
Investigate what happens when aqueous solutions are electrolysed using inert electrodes. This should be an investigation involving developing a hypothesis.
Check your understanding with these quick common questions. Use the drop down boxes to see the correct answers.
Electrolysis
Reacting an acid and a metal oxide together makes a salt. This can be separated from water through filtration and evaporation.
This is a procedure not an investigation. You could be asked to consider the size of crystals produced with different drying temperatures.
You may be asked to choose the correct acid and solid.
Hydrochloric acid = Chloride salt
Nitric acid = Nitrate salt
Sulfuric acid = Sulfate
Electrolysis cell, power supply, inert graphite electrodes, electrolyte solution.
Accuracy can be improved by measuring with a balance that has a higher resolution - more decimal places, to measure the mass of the electrodes
Validity can be improved by ensuring voltage, starting mass of the electrodes, concentration of any solutions are kept the same.
At the Cathode (reduction happens)
The positive ions gain electrons (reduced)
A metal that is not very reactive will be produced negative electrode (Cathode)
In aqueous solutions. e.g. Copper Sulfate (aq) -
Hydrogen is produced when the metal is more reactive (Sodium, magnesium, potassium)
If the metal is less reactive - Silver, Copper etc, the metal is produced.
At the Anode (Oxidation happens)
Negative ions are produced
If halide (Chorine, Bromine etc) - the halogen is produced
If not, oxygen is produced
Pour electrolyte into a beaker and insert two inert electrodes.
Connect to the power supply and switch on.
Observe products at each electrode.
Test gases collected with glowing or lighted splint.
Making Salts
Making a pure and dry salt such as Copper Chloride, Copper sulphate, Zinc nitrate.
Check your understanding with these quick common questions. Use the drop down boxes to see the correct answers.
Making Salts
Reacting an acid and a metal oxide together makes a salt. This can be separated from water through filtration and evaporation.
This is a procedure not an investigation. You could be asked to consider the size of crystals produced with different drying temperatures.
You may be asked to choose the correct acid and solid.
Hydrochloric acid = Chloride salt
Nitric acid = Nitrate salt
Sulfuric acid = Sulfate
Bunsen burner, beaker, evaporating dish, tripod, gauze, filter funnel and paper, dilute acid, metal oxide or carbonate.
Choose correct salts - How do you produce a chloride, sulfate or nitrate?
Accuracy can be improved by measuring with a balance that has a higher resolution - more decimal places.
Validity does not apply.
Does not apply.
Warm dilute acid gently.
Add metal oxide/carbonate until no more reacts (excess solid remains).
Filter to remove excess.
Evaporate the filtrate until crystals start to form, then leave to cool and dry.