Chapter 11

Please upload your full solution to the following problem. For the experimental isotherm data given below, determine the Freundlich and Langmuir isotherm parameters. Apply linear regression to determine the isotherm parameters. A spreadsheet can be used for this purpose. Which of the two isotherms better describes the data? Experimental data: Carbon type: F-400 Carbon size: 200 × 400 . Chemical: Trichloroethene, C₂HCl3 (131.39 g/mol) Temperature: 13 C pH: 7.5-8 Equilibrium time: 31 days ● Ⓡ B B Sample number 123456 TCE Liquid-Phase Concentration CA. μmol/L 23.6 6.67 3.26 0.322 0.169 0.114 TCE Adsorbent-Phase Concentration 9A, μmol/g 737 450 318 121 85.2 75.8 2

Which one of the following statements is not correct about MSDS? A It provides single reference for all information about hazardous Chemicals. It is based on the recommendation of the United Nation's Committee of Experts on Globally Harmonized B System of Classification and Labelling of Chemical; It does not contain information on physical and chemical properties of the material, potential hazards of the material and how to work safely with these materials. Material Safety Data sheet forms the important elements of effective Chemical Hazards Communication D System.

The first-order degradation rate constant k was determined to be 0.0125/day for contaminant A and 0.0030/day for contaminant B in a soil. Calculate the half-life T1/2 and the 95% dissipation time for these contaminants in the soil. Compare the persistence between the two contaminants.

18. Jet is an undergraduate chemistry student, he’s out in the laboratory trying to determine the volatile organic compounds as well as overall protein content of the leaf and stem of a malunggay (Moringa oleifera). He subjected the leaf and stem in a separate digestion reaction (treatment of sulfuric acid), afterwards he subjected the products to high temperature induction to get a dry ash like substance. Which type/s of chemical analysis did Jet employ to reach his objective?I. Qualitative AnalysisII. Quantitative Analysis III. Instrumental Chemical AnalysisIV. Wet Chemical AnalysisA. II & IV onlyB. I & IV onlyC. I, II & IV onlyD. I, II, III, IV

If some of the analytes were found to be out of range after doing the Quality Control and the machine repeatedly gives invalid result. What are the possible problem and best solution as a Medical Technologist?

Chemistry An aquifer contaminated with petroleum is found to have the following component concentrations at a particular site: benzene158 ppm toluene124 ppm ethylbenzene91 ppm xylene45 ppm n-heptadecane161 ppm pristane  84 ppm Provide an estimate for the age of the spill at this site using (a) BTEX ratio and (b) nC17:Pr ratio. Show your calculations and use units throughout. Give proper s.f. for the answer.

Here is a use objective for a chemical analysis to be performed at a drinking water purification plant: “Data and results collected quarterly shall be used to determine whether the concentrations of haloacetates in the treated water demonstrate compliance with the levels set by the Stage 1 Disinfection By-products Rule using Method 552.2” (a specification that sets precision, accuracy, and other requirements). Which one of the following questions best summarizes the meaning of the use objective?(i) Are haloacetate concentrations known within specified precision and accuracy?(ii) Are any haloacetates detectable in the water?(iii) Do any haloacetate concentrations exceed the regulatory limit?

7. Determine the effective diffusivity for a substrate passing through each of the following membranes: The substrate has a free solution diffusivity (D.,.) of 8.13 * 106 cm²/s and has a molecular radius of 7.54 Å (Angstroms). Membrane Type Mean pore diameter (nm) Porosity (%) Tortuosity Cellulose-1 12.16 67.9 2.97 Cellulose-2 9.65 78.7 1.76 Which membrane would you recommend using to avoid diffusion-limited reactions? Acrylic Fiber 8.72 85.9 3.83

1) A polyester made from sebacic acid (CAS# 111-20-6) and 1,6-hexanediol (CAS# 629-11-8) has the molecular weight fractionation listed below. Calculate an appropriate average molecular weight for this polyester. Source: Batzer, H., Macromolecular Chemistry and Physics 5

what is the principle of GC-MS?

Concentration of AR Stock Solution (ppmppm) 21.22   Unrounded Rounded Concentration of AR Stock Solution (μMμM) 42.7461 42.7