Chemical equilibrium in mineral water
Chemicals: bromine-cresol green BKG, soda, tap water, ethanol
Procedure: BKZ was dissolved in ethanol to 0.1% solution. Tap water is colored blue in distilled gold. Soda is poured into a polyethylene bottle and allowed to freeze. After the pour indicator on ice while heating and melting ice changes color from gold through green to blue. In retrospect cooling, the color changes to green.