Why 16 ppm Mn synthetic solution precipitates when pH adjusted to 7?

I have prepared 16 ppm Mn synthetic solution from Mn standard solution 1000mg/L. The pH was about 2. I added 0.5 M NaOH drop wise to raise the pH to 7. But at pH about 5++, I noticed brown...

14 September 2022 8,498 0 View