Brownlee Electrolysis Apparatus Including Battery Jar

Great for use in both lectures and hands-on activities! This unit consists of an acid-proof, non-porous insulating support with a spring clip for holding test tubes, binding posts and two platinum electrodes. The supports fit a 4 1/2 x 5" battery jar and holds a 150mm x 18mm test tube. Platinum electrodes and instructions are included. The unit operates on a 6V battery or 10V DC power supply. The key process of electrolysis is the interchange of atoms and ions by the removal or addition of electrons from the external circuit. The required products of electrolysis are in some different physical state from the electrolyte and can be removed by some physical process. An electrical potential is applied across a pair of electrodes immersed in the electrolyte. Each electrode attracts ions that are of the opposite charge. Positively-charged ions (cations) move towards the electron-providing (negative) cathode, whereas negatively-charged ions (anions) move towards the positive anode. At the electrodes, electrons are absorbed or released by the atoms and ions. Those atoms that gain or lose electrons to become charged ions pass into the electrolyte. Those ions that gain or lose electrons to become uncharged atoms separate from the electrolyte. The formation of uncharged atoms from ions is called discharging. The energy required to cause the ions to migrate to the electrodes, and the energy to cause the change in ionic state, is provided by the external source of electrical potential.