1
answer
0
watching
152
views
6 Nov 2019
Integrated Rate Laws: Using the Graphing Method If we wish to determine the order of the reaction we can often do so by using the graphing method. In this method, we start from a set of data where [A] changes as a function of time. The integrated rate laws for each reaction order (Zero, First and Second) can be written as the equations for a straight line Plot the data for each potential reaction order in your calculator and do a linear regression for each. By comparing the R- factor (should appear with the linear regression line in your calculator) of the three lines, you can tell which is the best straight line (R closest to 1.0). Note: It is obvious that anyone could just roll through the choices to get the correct answer, however, this set is your opportunity to practice/develop your skill with this method before you are tested on it. If [A] vs time is linear, it is Zero order in [A] If In[A] vs time is linear, it is First order in [A] If 1/[A] vs time is linear, it is second order in [A] a) Determine the reaction order from the concentration-time data below Time [Reactant] (seconds)(M) 0 0.250 Second Order First Order Zero Order 0.216 2 0.182 3 0.148 4 0.114 5 0.080 b) What are the units for the rate constant in this reaction? 1/sec 1/[M] sec 1/[M]sec [M]/sec 2 Show transcribed image text
Integrated Rate Laws: Using the Graphing Method If we wish to determine the order of the reaction we can often do so by using the graphing method. In this method, we start from a set of data where [A] changes as a function of time. The integrated rate laws for each reaction order (Zero, First and Second) can be written as the equations for a straight line Plot the data for each potential reaction order in your calculator and do a linear regression for each. By comparing the R- factor (should appear with the linear regression line in your calculator) of the three lines, you can tell which is the best straight line (R closest to 1.0). Note: It is obvious that anyone could just roll through the choices to get the correct answer, however, this set is your opportunity to practice/develop your skill with this method before you are tested on it. If [A] vs time is linear, it is Zero order in [A] If In[A] vs time is linear, it is First order in [A] If 1/[A] vs time is linear, it is second order in [A] a) Determine the reaction order from the concentration-time data below Time [Reactant] (seconds)(M) 0 0.250 Second Order First Order Zero Order 0.216 2 0.182 3 0.148 4 0.114 5 0.080 b) What are the units for the rate constant in this reaction? 1/sec 1/[M] sec 1/[M]sec [M]/sec 2
Show transcribed image text Sixta KovacekLv2
4 Feb 2019