GIPHOTOSTOCK / SCIENCE PHOTO LIBRARY GIPHOTOSTOCK / SCIENCE PHOTO LIBRARY
Buffer and water comparison. Here, two beakers are filled with 40 mL of pH=7 buffer (left) and water (right). Universal indicator is added to both solutions. Initially the colour is green indicating that both solutions are neutral (frame 1 from top). Then 0.1 M hydrochloric acid (HCl) is added in increments of 1 mL to both solutions. After the first 1 mL of HCl, water changes its colour to red thus becoming acidic (frame 2). It takes a total of 14 mL of HCl for the buffer to start changing its colour (frame 3) and 17 mL to become acidic (frame 4).
Model release not required. Property release not required.