Electrolysis (Paper 1)

Question 1

What is electrolysis?

Answer 1

The breaking down of a substance using electricity.

Question 2

What forms at the Cathode in an aqueous solution?

Answer 2

If H+ ions and metal ions are present then hyrdrogen gas is produced if the metal is more reactive than hydrogen. If the metal is less reactive than Hydrogen then a solid layer of the pure metal is produced instead

Question 3

What forms at the Anode in an aqueous solution?

Answer 3

If OH- and halide ions (Cl-, Br-, and I-) are present,molecules of chlorine, bromine or iodine will be formed. If no halide ions are present then oxygen is formed.

Question 4

Do the products of the reaction change at the cathode or anode in a molten substance?

Answer 4

No

Question 5

How do you set up electrolysis for an aqueous solution?

Answer 5

-Get two inert electrodes (graphite or platinum electrodes)
-Clean the surfaces of the electrodes using some emery paper (or sandpaper)
-Place the electrodes into a beaker with the electrolyte
-Connect the electrodes to a power supply using crocodile clips and wires

Question 6

How do you set up electrolysis for a molten ionic substance?

Answer 6

-Put the solid ionic substance in a crucible
-Heat the crucible with a bunsen burner until the solid is molten. You should do this in a fume cupboard to avoid the release of toxic fumes in the room
-Once the solid is molten, dip two clean, inert electrodes into thr electrolyte
-Then connect the electrodes to a power supply using wires and clips