Water consequently turns to grape juice to milk.
name: The color of the solution is changed in a number of consequent acid-base reactions.
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The color change, the precipitate and gas formation are caused by a number of chemical reactions which take place when solutions are mixed together. Phenolphtalein is colorless in neutral environment so the first solution is clear and looks like common water. In alkaline solutions the indicator changes its color to pink making the solution resemble grape juice. When the content of glass 2 is poured to glass 3 acid neutralizes the base and pH is shifted back to neutral.
2NaOH + H2SO4 → Na2SO4 + H2O
The solution is colorless again (lemonade).
Mixing of acidic solution with NaHCO3 in glass 3 gives bubbles of carbon dioxide:
H2SO4 + 2NaHCO3 → Na2SO4 + 2H2O + 2CO2
In glass 4 the formation of a white cloudy precipitate is observed. The fake milk consists of insoluble barium sulfate and water.
Na2SO4 + Ba(NO3)2 → BaSO4 + 2NaNO3
In glass 5 barium sulfate stays unchanged but solution pH is alkaline again like it was in glass 2. Phenolphtalein turns pink.