Rate of Reaction

• What does the rate of chemical reactions refer to?

  The speed of reactants turning into products
• Why is it important to measure the rate of a reaction?

  To understand how fast reactants are used up
• How can we measure the rate of a reaction?

  By measuring reactants used or products formed
• What are the two equations for calculating the rate of reaction?

  Reactants used/time or products formed/time
• What units can be used to measure quantities in the rate of reaction?

  Grams or cm cubed
• If 180 cm cubed of hydrogen is produced in 2 minutes, what is the rate?


  1.5 cm cubed per second
• How do you convert 2 minutes into seconds?

  120 seconds
• If 3 grams of magnesium takes 4 minutes to disappear, what is the rate?

  0.0125 grams per second
• What do the calculated rates of reaction represent?

  The average rates throughout the entire reaction
• How does the rate of reaction change over time?

  • Starts fast with many reactants
  • Slows down as reactants are used up
  • Graphs show decreasing mass of reactants or increasing volume of products
• What does the graph of mass of reactant remaining look like over time?

  Starts high, falls rapidly, then slows
• What does the graph of volume of product produced look like over time?

  Starts at zero, increases quickly, then levels off
• What other units can be used for measuring rates of reaction?

  Moles or decimet cubed per second
• How do you calculate the rate in moles per minute if 0.6 moles of magnesium are used in 2 minutes?

  0.3 moles per minute
• What will the next video cover regarding the rate of reaction?

  • Calculating the rate of reaction at a specific time
  • Differentiating from average rate calculations