Rates 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
• 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 g of magnesium takes 4 minutes to disappear, what is the rate?

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

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

  • Starts fast with many reactants
  • Slows down as reactants are used up
• How can we visualize the rate of reaction on a graph?

  • Time on x-axis
  • Mass of reactant or volume of product on y-axis
  • Graphs show changes over time
• If 0.6 moles of magnesium are used in 2 minutes, what is the rate in moles per minute?

  0.3 moles per minute
• What units can be used to measure the rate of reaction?

  • Grams per second
  • cm cubed per second
  • Moles per minute
  • Decimet cubed per second