- Lead(II) bromide is a binary ionic compound meaning that it is a compound consisting of just two elements joined together by ionic bonding.
- When these compounds are heated beyond their melting point, they become molten and can conduct electricity as their ions can move freely and carry the charge.
- These compounds undergo electrolysis and always produce their corresponding element.
- To predict the products of any binary molten compound first identify the ions present.
- The positive ion will migrate towards the cathode and the negative ion will migrate towards the anode.
- Therefore the cathode product will always be the metal and the product formed at the anode will always be the non-metal.
Electrolysis of Lead (II) Bromide
Diagram Showing the Electrolysis of Lead (II) Bromide
- Add lead(II) bromide into a crucible and heat so it will turn molten, allowing ions to be free to move and conduct an electric charge.
- Add two graphite rods as the electrodes and connect this to a power pack or battery.
- Turn on the power pack or battery and allow electrolysis to take place.
- Negative bromide ions move to the positive electrode (anode) and lose two electrons to from bromine molecules. There is bubbling at the anode as brown bromine gas is given off.
- Positive lead ions move to the negative electrode (cathode) and gain electrons to form grey lead metal which deposits on the surface of the electrode.
Anode: Bromine gas
Cathode: Solid lead metal