Jagube
Esteemed member
While working with Ca(OH)2 (lime), I observed a behavior that seemed to go against my (limited) understanding.
While basifying an acidic solution with lime, I noticed that to bump the pH to higher levels, I had to add more of it, even though there was undissolved lime in the system already that wasn't dissolving further (meaning: the solution was saturated).
Then when I reached pH ~12, let the undissolved lime settle at the bottom and decanted the supernatant off, the latter had a lower pH, maybe 10.
It would thus seem that undissolved lime in a lime-saturated solution rises the pH. How is that possible? Or did I make an error?
While basifying an acidic solution with lime, I noticed that to bump the pH to higher levels, I had to add more of it, even though there was undissolved lime in the system already that wasn't dissolving further (meaning: the solution was saturated).
Then when I reached pH ~12, let the undissolved lime settle at the bottom and decanted the supernatant off, the latter had a lower pH, maybe 10.
It would thus seem that undissolved lime in a lime-saturated solution rises the pH. How is that possible? Or did I make an error?