6.2 Changes at the electrodes

Question 1

What happens to ions during electrolysis

Answer 1

• positive ions move towards the cathode, gain electrons, reduction
• negative ions move towards the anode, lose electrons, oxidiation

Question 2

What solution does salt have when it dissolves in water and what happens to the ions

Answer 2

brine/ sodium chloride solution

• Sodium ions and chloride ions split up
• Na+ ions and Cl- ions
• Water molecules also split up
• H+ ions and OH- ions

It produces hydrogen, chlorine and sodium hydroxide

Question 3

How does water affect the products of electrolysis

Answer 3

When electrolysis happens in aqueous solution, the less reactive element is usually produced at the cathode

At the anode oxygen is given off from discharged hydroxide ions produced from water
a halogen is produced if the electrolyte is a soultion of a halide

Question 4

Whats the easiest to discharge at the anode

Answer 4

halide ion