HA ↔ H+ + A- Phenolphthalein is typically used in this demo because its change from colorless to bright pink is easy to see in large lecture halls, but universal indicator could also be used.

There is no prep box for this demo in the demo room. Chemicals are on the shelves and the plastic sheet is on the back of demo manual. The ferric thiocyanate solution is blood red in color, and the ...