Comparative Study on the Stability of Mn(III) Ion Prepared by Different Methods in H2SO4 and H3PO4 Media

The time-periods required for the % of Mn(III) to disappear from the solution and the half-life of Mn(III) was studied in 7 mol dm-3H2SO4and 7 mol dm-3H3PO4media at ambient conditions at three different Mn(III) concentrationsviz. 4.98, 1.94 and 1.04 mmol dm-3using spectrophotometric method. Half-life periods in the presence of 7 mol dm-3H2SO4are more than those in presence of 7 mol dm-3H3PO4. The time-periods required for the 1% of Mn(III) to disappear that for H2SO4medium from 1.94 mmol dm-3, Mn(III) solutions prepared from solid form is about 20 days, 10 days for electro-generated Mn(III) and 6 days for chemical oxidation method.