Measuring rate of reaction from a graph

• What can graphs measure in a reaction?

  Mean rate and rate at specific time
• How is the rate of reaction calculated?

  By dividing reactants used or products formed by time
• Why does the rate of reaction slow down over time?

  Reactants are used up during the reaction
• What does a steep curve on a reaction graph indicate?

  High rate of reaction
• What happens to the graph once all magnesium is used up?

  The graph plateaus
• How do you calculate the mean rate of reaction over a period using a graph?

  • Find the time on the x-axis
  • Draw a dashed line to intersect the curve
  • Draw a line to the y-axis to find volume
  • Divide volume by time to get mean rate
• How do you find the rate of reaction at a specific time?

  Calculate the gradient of the tangent
• What is a tangent in the context of a reaction graph?

  A straight line touching the curve at one point
• How is the gradient of the tangent calculated?

  Change in y divided by change in x
• How would you find the rate of reaction using a magnesium graph?

  • Start with initial grams of magnesium
  • Find the time point on the curve
  • Draw a tangent at that point
  • Calculate change in y and change in x
  • Divide change in y by change in x for rate