Problem: A colored dye compound decomposes to give a colorless product. The original dye absorbs at 608 nm and has an extinction coefficient of 4.7 104 M-1 cm-1 at that wavelength. You perform the decomposition reaction in a 1-cm cuvette in a spectrometer and obtain the following data: Time (min)  Absorbance at 608 nm 01.254300.941600.752900.6721200.545Determine the rate constant for the reaction.

FREE Expert Solution

We are being asked to determine the rate constant for the reaction given the following data:


 Time (min)  Absorbance at 608 nm 
01.254
300.941
600.752
900.672
1200.545


Recall: In chemical kinetics, a reaction rate constant or reaction rate coefficient, k, quantifies the rate of a chemical reaction

For a zero-order reaction, the integrated rate law is given by

At = -kt + A0

where k = rate constant, [A]t = final concentration, [A]0 = initial concentration, t = time. plot of [A] versus time will be a straight line with slope of –k.


For a first-order reaction, the integrated rate law is given by

lnAt = -kt + lnA0

where k = rate constant, [A]t = final concentration, [A]0 = initial concentration, t = time. plot of ln[A] versus time yields a straight line with a slope of –k.


100% (51 ratings)
View Complete Written Solution
Problem Details
A colored dye compound decomposes to give a colorless product. The original dye absorbs at 608 nm and has an extinction coefficient of 4.7 104 M-1 cm-1 at that wavelength. You perform the decomposition reaction in a 1-cm cuvette in a spectrometer and obtain the following data:


 Time (min Absorbance at 608 nm 
01.254
300.941
600.752
900.672
1200.545


Determine the rate constant for the reaction.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Rate Law concept. You can view video lessons to learn Rate Law. Or if you need more Rate Law practice, you can also practice Rate Law practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Song's class at University of the District of Columbia.