Chapter 2, Problem 6P

Chloroform is used as an internal standard in the determination of the pesticide deltamethrin. To calibrate the method a mixture of 0.500 mM of chloroform and 0.800 mM of deltamethrin which produced signals of 15.3 (w.a.) and 10.1 (w.a.) for chloroform and deltamethrin, respectively. To prepare the sample, 10.00 mL of a sample of unknown concentration of deltamethrin and 10.10 μL of pure chloroform (FW = 119.39 g/mol, ρcloroformo = 1.484 g/L) is homogenized and diluted with water to the 100.00 mL mark in a volumetric flask. After preparing the sample, the observed signals of 30.0 (a.u.) and 20.7 (a.u.) for chloroform and deltamethrin, respectively, are observed. 1. Determine the response factor (K) for the method.  2.Determine the millimolar (mM) concentration of chloroform added to the sample. Remember that the final volume of the solution is 100.00 mL. 3.Determine the millimolar (mM) concentration of deltamethrin in the sample.  4.If the concentration of deltamethrin should not…

4c. Calculate the values of Mn, Mw, Mz and polydispersity index for a polymer mixture having equivalent moles of two polymers with exact molecular weight being 2,000 Dalton and 10,000 Dalton.

Seawater was spiked with phosphate to achieve a quantifiable range of phosphate concentrations by spectroscopy. What components of the spectrophotometer or sample preparation could be changed that would improve detection limits?

The student was supposed to measure the pH of a 0.1 M hydrochloric acid solution. For this purpose, he used a pH-meter and obtained the following results: 0.90, 0.93, 1.04, 1.02. Present the appropriate graphic and statistical elaboration of the performed analysis and confirm whether the applied pH-meter worked properly.

The following calibration data were obtained by an atomic absorption spectrophotometric (AAS) method for the determination of mercury in an herbal product. (show complete solution) 1. What is the detection limit for the method? 2. What is the limit of quantitation for the method?

What is the correlation of the density of the saltwater mixture and the brightness of the bulb?

The absorption coefficient of O2 in seawater at 0°C is 1.7 mmol/L.What is the concentration of O2 if the O2 partial pressure is 0.1atm? Express your answer first in mmol/L, then in mL/L.

in the determination of Keq in spectrophotometry, why is it that [KSCN] is lower in the preparation of unknown solutions.

Seawater was spiked with phosphate to achieve a quantifiable range of phosphate concentrations by the spectrophotometer. What components of the spectrophotometer or sample preparation could be changed that would improve detection limits?