Increasing the surface area of solid reactants only serves to increase the frequency of collisions between reactant molecules.

Large granules of calcium carbonate when placed in acid solution react slowly to produce carbon dioxide gas. When the calcium carbonate is crushed into a fine dust however, the reaction rate increases significantly.

Click to see a 120 kb video of the reaction between powdered calcium carbonate and acid.

Fireworks manufacturers often modify the surface area of solid reactants to achieve desired effects.

Click to see a 120kb video of home-made sparkler with reduced surface area burn slowly.

Click to see a 120kb video of the same mixture ground to a fine powder. Notice the increase in the rate of reaction

Click to see a demonstration of the flammability of fine, carbon based powders

Sparklers are a dynamic demonstration of the energy release during oxidation reactions. It easy to make home-made sparklers. Ask your teacher.

Nitrous oxide gas is produced when copper reacts with nitric acid. Click to see a 120kb

10.0 grams of small pieces of copper are placed in a beaker with concentrated nitric acid. Explain how the rate at which gas is produced would differ if a 10.0 gram solid block of copper was used instead.