Measuring rates of reaction from a graph

• On a concentration/time graph of a chemical reaction, what does a steep gradient of the line indicate?

  That the rate of reaction was fast
• Why do concentration/time graphs plateau?

  The graph plateaus as the reactants are used up
• What is the formula to find the gradient of a line?

  Change in y divided by change in x
• How do you find the rate of reaction at a particular point on a concentration/time graph?

  1. Draw a tangent to the line at that point
  2. Calculate the gradient of the tangent by picking 2 points on the line and doing 'change in y divided by change in x;
  3. The gradient of this tangent is the rate