INFLUENCE OF TEMPERATURE ON THE ELECTRO-DISSOLUTION OF TIN IN NACL AQUEOUS-SOLUTION AT PH4

The influence of temperature in the range 25 to 80°C on the dissolution of tin was investigated in an acidic solution at pH4 containing 0.1 to 1 m NaCl. The corrosion current is slightly dependent on both the temperature and the Cl- ion concentration. The main dissolution characteristics of tin are {Mathematical expression} with an apparent energy of activation of 33 kJ mol-1 as long as the electrode surface is bare, whence it is deduced that the dissolution process is the same over the entire range of temperatures and concentrations under consideration. The behaviour of tin is different when a precipitate is formed on its surface, which is generally observed at E>-0.5 Vsce. The changes occurring on the electrode surface were observed by semi-quantitative energy dispersive X-ray analysis and scanning electron microscopy. © 1990 Chapman and Hall Ltd.