In this activity: Students conduct a reaction with citric acid and baking soda in a universal indicator solution. The resulting chemical reaction produces a gas, causes a color change with an ...

HA → H+ + A- Universal indicator is a wide range indicator and is composed of several different indicators. This allows it to exhibit a wide range of colors at different pH values – visualized here as ...

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.

When pure water is dropped into a solution of universal indicator, the indicator stays green. This indicates a pH value of 7 and tells us that water is neither alkaline or acid, but neutral.

MOSCOW, November 4. /TASS/. Russia is concerned about certain states’ attempts to establish the so-called universal indicators of conflicts, allowing third parties to interfere, Russian Foreign ...