TURTLE ROCK SCIENTIFIC / SCIENCE PHOTO LIBRARY TURTLE ROCK SCIENTIFIC / SCIENCE PHOTO LIBRARY
Editorial use only.
Phenolphthalein indicator. Phenolphthalein indicator changes its colour depending on the pH of the solution, it turns colourless in acidic solutions and pink/fuchsia in basic solutions. Here phenolphthalein solution (centre) is added to beakers with an acidic solution (left, 0.1 M sulfuric acid, H2SO4) and an alkaline solution (right, 0.1 M potassium hydroxide, KOH).
Model release not required. Property release not available.