MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY MARTYN F. CHILLMAID / SCIENCE PHOTO LIBRARY
Reaction rate demonstration. Both beakers contain 25 millilitres of hydrochloric acid and one gram of calcium carbonate (marble). In the beaker at left, the marble has been ground into a powder. In the beaker at right, it is in large chunks. This demonstrates the effect of surface area on reaction rate. The powder exposes far more of its surface to attack by the acid, which causes the reaction to proceed much more vigorously. In this reaction, carbon dioxide is released, which causes the bubbling.
Model release not required. Property release not required.