[candyman007]

Gibbsite is the most stable aluminum mineral found in nature. Its chemical formula is AL(OH)3 and it is only slightly soluble (K=3.0x10^-34) in natural waters having pH=6-8. It becomes much more soluble in acidic lakes and streams. Compare [Al^3+] in a lake having pH=5.0 with the solubility of Al(OH)3 in the biological fluid found in fish gills (pH=7.4). Does this issue have any relevance to the survival of fish in acidic lakes? Explain. I have no idea where to start.

[fledarmus]

Put away the chemistry for a second and just think of the words. What does it mean to say that Gibbsite is "soluble" in acidic lakes and streams? If it is only slightly soluble in natural waters having ph6-8, what would happen physically to the Gibbsite if you had it dissolved at pH 5 and then changed the pH to 7.4?