Mean Rate of Reaction

• What should you be able to do by the end of the video?

  Draw and interpret graphs of reactants or products in a chemical reaction and calculate the mean rate of a chemical reaction.
• How does the slope of a graph relate to the rate of a chemical reaction?

  • The steeper the slope, the faster the reaction.
  • A flat line indicates the reaction has stopped.
• What does a decreasing slope on a reaction graph indicate?

  The reaction is slowing down as fewer reactant molecules are available.
• What is the unit of measurement for the quantity of product formed if it is a gas?

  Centimeters cubed.
• How do you calculate the mean rate of a chemical reaction?

  • Mean rate of reaction = quantity of product formed / time taken
• If 60 grams of product is formed in 15 seconds, what is the mean rate of reaction?

  4 grams per second.
• What is the mean rate of reaction if 20 grams of product is formed in 40 seconds?

  0.5 grams per second.
• How do you calculate the mean rate of reaction from the quantity of reactant used?

  By dividing the quantity of reactant used by the time taken.
• If 30 grams of reactant is used in 10 seconds, what is the mean rate of reaction?

  3 grams per second.
• What is the mean rate of reaction if 150 grams of reactant is used in 75 seconds?

  2 grams per second.
• What happens to the rate of reaction as the quantity of reactant decreases?

  • The rate of reaction decreases.
  • This is due to fewer reactant molecules available to react.