I Review I Constants I Periodic Table An average reaction rate is calculated as the change in the concentration of reactants or products over a period of time in the course of the reaction. An instantaneous reaction rate is the rate at a particular moment in the reaction and is usually determined graphically, but it can also be calculated using calculus. How to use a plot to calculate the instantaneous reaction rate To calculate the instantaneous reaction rate graphically, first, plot the graph of concentration versus time. Then, draw the tangent line to the point in question. The absolute value of the slope of the tangent line is equal to the instantaneous rate at that point. The slope of a line is calculated by dividing the "rise" by the "run." The y intercept is equal to the absolute value of the "rise" and the x intercept is equal to the "run." The reaction of compound A forming compound B was studied and the following data were collected: Time (s) [A] (M) Part A 0. 0.184 200. 0.129 Plot the points given in the table to create the graph of A versus t. 500. 0.069 • View Available Hint(s) 800. 0.031 1200. 0.019 1500. 0.016 No elements selected 0.200 0.150 0.100 0.050 400 800 1200 1600 Select the elements from the list and add them to the canvas setting the appropriate attributes. Press (TAB to get to the main menu. [A] (M)