Problem: How would I approach this question using PHREEQC or equilibrium diagrams?
A very long time ago when I was in graduate school, a fellow graduate student was doing some experiments with montmorillonite ((N a, Ca)0.33(Al, M g)2(Si4O10)) where she had to adjust the pH of some montmorillonite suspensions. She was using 0.1M HCl and 0.1 M NaOH stored in glass bottles to make the adjustments. For some reason she always ended up with much more Si in her solutions then and she expected. What do you think was going on?