A vivid demonstration of dependence of overvoltage on the physical state of a metal deposited on the electrode

• Ali Mardan ^[1] ; Rumana Ajaz ^[1]
  1. [1] Applied Chemistry Division, PINSTECH
• Localización: Journal of chemical education, ISSN 0021-9584, Vol. 77, Nº 12 (December), 2000, págs. 1580-1580
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • A procedure for demonstrating the dependence of overvoltage (observed as rate of hydrogen discharge) on the physical state of metal deposited on the electrode (platinum metal vs platinum metal coated with a porous layer of platinum black) is described. The demonstration utilizes a platinum wire, a tin-lead alloy solder wire, a platinizing instrument, a platinizing solution, and a 1.5 M solution of HCl. When a piece of platinum wire with one end platinized and the other end having a solder spot is immersed in 1.5 M HCl solution, the rate of production of hydrogen bubbles is strikingly greater than when the wire has only a spot of solder on one end.