What solution can simulate ocean acidification for a classroom demonstration?

[Teacher in Suquamish]

I would like to do a classroom demonstration using plaster of paris (or something similar) shells dissolving in a low pH solution, simulating ocean acidification.

I would like the reaction to happen quite quickly in front of the classroom. What solution could I use to dissolve plaster of paris quickly? It doesn't have to be low pH, but visually simulating it. This will accompany another experiment using Bromothymol blue dye, so I will color the solution yellow. It would be great if the solution was odorless or low odor...

 

[Kevin McHugh]

What would be the purpose of the demonstration? The ocean is one heck of a buffer system, and resists small changes in pH. Using an acidic solution near the pH of the ocean would be a very boring exercise. If you want to demonstrate dissolution of seashells, use calcium carbonate and a dilute acetic acid solution.