C5 - Electrolysis

Question 1

Define electrolysis [1]

Answer 1

• The breakdown of an ionic compound when molten or in aqueous solution by the passage of electricity

Question 2

Describe inert electrode [1]

Answer 2

• Does not react with the electrolyte or products formed during electrolysis

Question 3

Describe electrolyte [1]

Answer 3

• Ionic compounds that are in the molten state or dissolved in water

Question 4

Describe anode [1]

Answer 4

• The positive electrode

Question 5

Describe cathode [1]

Answer 5

• The negative electrode

Question 6

Explain what happens to anions in electrolysis [2]

Answer 6

• Negative ions that are attracted to the anode
  + where they give up electrons (oxidised)

Question 7

Explain what happens to cations in electrolysis [2]

Answer 7

• Positive ions that are attracted to the cathode
  + where they gain electrons (reduced)

Question 8

Describe the rules for what forms at the anode [1]

Answer 8

• Hydrogen (from H+ in water) is produced
  +unless the cations in the ionic compound from the metal are less reactive than hydrogen