METHOD FOR MEASURING SURFACE AREA OF ZINC

摘要

PURPOSE:To enable easy measurement of surface area of zinc powder which is previously relatively difficult by using a prescribed reducing soln. thereby depositing uniformly manganese oxide on zinc surface with good reproducibility. CONSTITUTION:A zinc plate is immersed for about 30sec into potassium permanganate with alkalinity of sodium hydroxide which is an alkaline permanganic acid soln. kept at about 30 deg.C liquid temp. and immediately thereafter a mixed soln. composed of ethanol and water is added as a reducing soln. thereto to change the soln. from a purple to green or brown color thereby reducing the zinc plate. After the zinc plate is rinsed and dried, the zinc plate is immersed in a hydrogen peroxide solution acidic with hydrochloric acid to dissolve the manganese oxide on the zinc surface. The manganese of the soln. is quantitatively determined by a polarized Zeeman atomic absorption spectrophotometer and the amt. of the manganese deposited per specified area is calculated.