a. each your four runs, plot the recorded absorbance versus time data with a gra
ID: 1068954 • Letter: A
Question
a. each your four runs, plot the recorded absorbance versus time data with a graphing of program. For each run, determine the half-life of the crystal violet in seconds. If possible, look at the absorbance at the second half-life, too. Include print outs of your four plots with your report, showing the first half-life (and second half-life, if possible) on each. b. Using your pseudo first-order rate constants, k', for Runs 1 through 4, calculate the half-life of crystal violet for each run in seconds. (The values will be slightly different since they depend on the hydroxide ion concentration.) c. For each run, compare the half lives determined in part a to the calculated half lives in part b Comment on your results.Explanation / Answer
Half-life
a) From run 1
Second order
t1/2 = 1/k[A]
k = 0.0861 M-1.s-1
So,
t1/2 = 1/0.0861 x 2.5 x 10^-5 M
= 4.64 x 10^5 s
b) for pseudofirst order
run 3
t1/2= ln2/k
k = 0.001806 s-1
so,
t1/2 = ln(2)/0.001806
= 383.80 s
c) the half-life for pseudofirst order kinetics is much lower than the second order reaction.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.