Electric Cell Pre-Quiz

Why does the bulb only glow when lead(II) bromide is melted?

• Solid lead(II) bromide does not contain ions.

• Ions can move through the whole circuit when lead(II) bromide melted.

• Ions are only formed when lead(II) bromide melts.

• Electrons flow through molten lead(II) bromide.

Aqueous lithium chloride is electrolysed using inert electrodes. What are the products at the electrodes?

• Anode: lithium

  Cathode: chlorine

• Anode: chlorine

  Cathode: hydrogen

• Anode: oxygen and water

  Cathode: hydrogen

• Anode: oxygen and water

  Cathode: chlorine

What is the reaction at the cathode when aqueous sodium chloride is electrolysed?

• Na+ ions gain electrons and reduced

• Na+ ions lose electrons and reduced

• H+ ions gain electrons and reduced

• H+ ions lose electrons and reduced

Blue aqueous copper(II) nitrate is electrolysed in beakers A and B as shown.

Identify the electrodes, 1 to 4, which act as the anode in beakers A and B.

• 1 only

• 1 and 2 only

• 1 and 3 only

• 2 and 4 only

• 3 and 4 only

Aqueous copper(II) nitrate is electrolysed in beakers A and B as shown.

What is the half equation at electrode 1?

Aqueous copper(II) nitrate is electrolysed in beakers A and B as shown.

Electrodes 2, 3 and 4 show a change in mass. Which statements explains this observation?

Aqueous copper(II) nitrate is electrolysed in beakers A and B as shown.

Which statement about the electrolyte in beakers A and B are correct?

• blue solution decolorizes in A only

• blue solution decolorizes in both A and B

• there is no change of pH in both solutions

• pH changes in A but not in B

In beaker A, effervescence occurs at electrode 1 and electrode 2 increase in size.

What is the correct overall equation in beaker A?