Pmt

• Rate of reaction can be calculated by:

  1. reactants used / time
  2. products formed / time
• Units for rate of reaction:

  1. Mass: g/s
  2. Volume: cm3/s
• What equipment can be used to collect gas?

  gas syringe

  inverted measuring cylinders
• The rate of reaction decreases during the chemical reaction as there is less reactant molecules available to react, which ends up with the curve levels off
• Collecting gas with gas syringe

  
• Collision theory:

  • a chemical reaction only happens if the reactant particles collide with enough energy
  • the minimum amount of energy needed for a reaction is called activation energy
  • for a reaction to happen, the reacting particles must successfully collide with one another
• Factors that can affect the rate of reaction:

  • Temperature
  • Concentration
  • Surface area
  • Pressure
  • Catalyst
• Increase temperature:

  • Reactant particles gain kinetic energy
  • They move faster
  • Collide more often
  • Collide with more energy

  -> Increase rate of reaction

  
• Increase surface area:

  • Increase surface area : volume ratio
  • More surface area exposed to other reactant, so more surface area for other reactant particles to collide with
  • More frequent and successful collisions

  -> Increase rate of reaction

  
• Increase concentration:

  • More particles in the same amount of space
  • Particles are closer together
  • More frequent collisions

  -> Increase rate of reaction

  
• Increase pressure:

  • More reactant particles in a given volume
  • Higher pressure, particles are closer to each other
  • More frequent collisions

  -> Increase rate of reaction

  
• How to measure the rate of reaction?

  Draw a tangent to the curve