Ch6 Electrolysis

Question 1

electrolytes

Answer 1

ionic solution that can conduct electricity

- ions are free to move around and can carry charge

Question 2

PANIC

Answer 2

positive anode

negative is cathode

Question 3

negative electrode

Answer 3

cathode

Question 4

positive electrode

Answer 4

anode

Question 5

what ion moves to the cathode

Answer 5

positive metal ions
opposite charges attract
they become reduced
- gain electrons

Question 6

what ion moves to the anode

Answer 6

negative non-metal ions
opposite charges attract
they become oxidised
- lose electrons

Question 7

Process of electrolysis

Answer 7

1. Pass an electric current through electrolytes
2. Causes ions to move oppositely charged inert electrodes
3. Ions are discharged, producing elements

Question 8

Electrolysis to extract metals

Answer 8

used if metal is too reactive to be displaced by carbon

Question 9

electrolysis of aqueous solutions at anode

Answer 9

oxygen is produced unless the solution contains halide ions

Question 10

electrolysis of aqueous solutions at cathode

Answer 10

Hydrogen is produced if the metal is more reactive than hydrogen

Question 11

electrolysis of aqueous solutions

Answer 11

water molecules break down producing H+ ions and OH- ions that become discharged

Question 12

Electrolysis of aluminium oxides

Answer 12

cyolite reduces the melting point

positive Al3+ ions move towards the cathode and become reduced
Al3+ + 3e- -> Al

negative O2- ions move toward the anode and become oxidised
2O2- -> O2 + 4e-

Question 13

carbon electrode

Answer 13

when oxygen reacts with hot carbon electrodes, carbon dioxide is produced
they gradually burn away and need to be replaced regularly