surface area

• here, the solid is reacting with particles in solution, or gas

  the particles in solution can only react with particles on the surface of the solid

  a lot of particles in the solid are not on the surface, so cannot react

  
• greater surface area of solid = more collisions per second = increased rate
• smaller sized solid reactant have a greater surface area to volume ratio than larger blocks

  as they have more particles on the surface, so there are more collisions per second, so increased rate
• marble chips contain calcium carbonate

  reacts with hydrochloric acid = co2 gas

  = measure volume of co2 gas in measuring cylinder --> determine rate

  --> change the surface area of the marble chips

  
• problem: measuring volume of gas in measuring cylinder because the bubbles can be rapid

  more accurate to use gas syringe

  
• as co2 is produced, the mass decreases

  cotton wool allows co2 gas to escape, and prevents acid from splashing out of flask, if it did then it would decrease mass more than it should = anomaly