Parts 1: The Effect of Concentration
Please choose one experiment (1-5) and perform the following calculations.
(1) Show one calculation of the initial concentration of I^(-)and S_(2)O_(8)^(2-). (This is the concentration when the reaction begins)
(2) Show one calculation of the rate of reaction 1 with the unit of (M)/(s) (molar per second). The rate of reaction can be calculated from Delta (I_(2))/(Delta )t. Delta [I_(2)] is the amount of I_(2) produced from reaction 1 . These I_(2) react with S_(2)O_(3)^(2-) and won't become I_(3)^(-)until S_(2)O_(3)^(2-) all has been consumed. Therefore, you can determine Delta [I_(2)] from the amount of S_(2)O_(3)^(2-).
(3) Show a calculation of the average rate of reaction.
(4) Show how you determine the reaction order ( x ) of I. You can use experiment 1 and 2 or 2 and 3 or 1 and 3 to determine the reaction order of I^(-). Pick a pair of experiments and use the initial rates method (Example calculation on page 9) to find the value for x. Pick a different combination of experiment 1-3 to verify the value obtained for x. Show the calculated value with significant figures and then round the value to the nearest whole number.
(5) Show how you determine the reaction order ( y ) of S_(2)O_(8)^(2-). Similar to the value of x, use experiment 2,4 and 5 to determine the value of y. Show the calculated value with significant figures and then round the value to the nearest whole number.
(6) Show how you determine an average rate constant (k). You will need to substitute x,y, and the rate of reaction to the rate law of reaction 1 . Then, calculate and report the rate constant (k) for each experiment with appropriate significant figures. Show only one calculation example in your report. Note that the unit of rate constants in a first-, second-, and third-order reaction are different. Make sure you show how you come up with the unit of the rate constant.
Rate of reaction 1=k[I^(-)]^(x)[S_(2)O_(8)^(2-)]^(y)
able[[Rate Law,Overall Reaction Order,Units for k
+Data Table 1 Experiment Trial Initial Initial Reaction Times # [I]M [S.0] M
Rate Average Rate (M/s) Rate Constant (M/s) K
1
1
0.09M 0.05M 48.00s,55.00 s,56 s
2
47.00s, 40.00 s, 43.00 s
3
60.00s.43.00 s.57.00 s