# Solubility problems

1. Aug 5, 2005

### hexa

Hello,

I'm currently abroad and have to learn for a chemistry exam which will take place the day after I'm back home. Unfortunately I've forgotten to take along a book and now have difficulties solving one type of problem, also as the local library doesn't have books in a language I understand and there's just one computer with very expensive internet connection here.

One example problem:

Chlorite Mg5Al2SiO3O10(OH)8 dissolves incongruently.

Write down the reaction assuming that H4SiO4^0 is part of that reaction.

If ground water at 25 degrees celsius with a molarity of 10^-3.38 is in equilibrium with chlorite and the ph is 8.5, what is the concetration of H4SiO4^0 in mg/l. Assume that a=m

Another problem:

Calculate the solubility of fluorite (CaF2) in water at 10, 20 and 30 degrees celsius and express the answer of Ca^2+ in mg/L (gamma = 1).

There are more, rather similar problems in previous exams. I just chose those two as representative examples. Please can someone solve these problems for me or at least explain to me how to solve them? If I had that book with me it would not be a problem to look it up myself but at the moment I'm only guessing around. No problems yet with other topics as they are explained nicely in the book I actually took along.

thanks a lot,
hexa