The following results were obtained for a spectrophotometric titration that was carried out at 600 nm to measure Cu2+in a water sample according to the reaction below:Cu2++ Trien → Cu(trien)2+
A 10.00 mL sample of water was used for this titration, and the following results were obtained upon the addition of increments of titrant to the sample:
|
Sample volume (mL)
|
Volume Trien (mL)
|
Absorbance
|
|
0.00
|
0.00
|
0.002
|
|
10.00
|
0.00
|
0.005
|
|
10.00
|
2.00
|
0.181
|
|
10.00
|
4.00
|
0.306
|
|
10.00
|
6.00
|
0.402
|
|
10.00
|
8.00
|
0.416
|
|
10.00
|
10.00
|
0.375
|
(a) What was the concentration of Cu2+in the original sample?
(b) Explain the shape of the titration curve obtained for this analysis. What does this curve tell you about the ability of the analyte, titrant and product to absorb light at the wavelength used for this titration?
(c) Use the information provided to estimate the value of the molar absorptivities for the analyte, titrant and product at 600 nm.