Surface area

• Effective surface area


  The surface area of solid reactants that can interact with particles in solution or gas
• Increasing the surface area of a solid reactant

  Increases the rate of the reaction
• Surface area to volume ratio

  • Smaller sized blocks of solid reactant have a greater surface area to volume ratio than larger blocks
  • More particles on the surface, more collisions per second, increases the rate of the reaction
• Investigating the effective surface area on the rate of reaction

  1. Use marble chips containing calcium carbonate

  2. React with hydrochloric acid to produce carbon dioxide gas

  3. Measure the volume or mass of carbon dioxide gas produced to determine the rate of reaction

  4. Change the surface area of the marble chips
• Measuring the volume of gas can be difficult due to rapid bubbles, a gas syringe gives more accurate results
• Measuring the mass of carbon dioxide gas lost can also be used to calculate the rate of reaction
• The cotton wool allows carbon dioxide to escape but prevents acid from splashing out, which could cause an anomalous result