Electrolysis

Aim : To study electrolysis

Meterial : Lead bromide powder

App : dry cells, connecting wires, carbon rods, crucible, tripod stand, pipeclay triangle, bunsen burner, bulb, switch.

Method :
1. The app is set up as shown in figure 1.
2. the switch is closed. The bulb is observed to see whether it lights up. The switch is then turned off.
3. The lead bromide powder is heated strongly until its melt. The switch is then closed again to allow electricity to flow through the molten lead bromide.
4. the changes at the bulb n carbon electrodes r observed and recorded.


State if lead bromide
1. Powder
2. Molten

Bulb
1. does not light up
2. lights up

changes at cathode
1. no chg
2. a shiny silver solid is deposited


chgs at anode
1. no chg
2. brown vapour is released.


Conclution : during elec, lead bromide decomposes to form lead n bromine.