Chemistry An aquifer contaminated with petroleum is found to have the following component concentrations at a particular site: benzene 158 ppm toluene 124 ppm ethylbenzene 91 ppm xylene 45 ppm n-heptadecane 161 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

Chemistry An aquifer contaminated with petroleum is found to have the following component concentrations at a particular site: benzene 158 ppm toluene 124 ppm ethylbenzene 91 ppm xylene 45 ppm n-heptadecane 161 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

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter31: Introduction To Analytical Separations

Section: Chapter Questions

Problem 31.13QAP

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An aquifer contaminated with petroleum is found to have the following component concentrations at a particular site: benzene 158 ppm toluene 124 ppm ethylbenzene 91 ppm xylene 45 ppm n-heptadecane 161 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.
Ali has measured the oxidative stability of palm oil sample under accelerated storage condition at 60*C for 6 days The following data were recorded for the peroxide value and p anisidine value of the palm oil after 5 days of storage time: Sample weight 1.0030 g Concentration of NazSzO3 = 0.001 N Volume of NazSzO3 titrated for sample solution = 1.35 ml Volume of NazSzO3 titrated for blank solution 0.20 ml Absorbance for sample solution = 0.907 Absorbance for blank solution 0.203 Calculate: i) peroxide value ii) p-anisidine value iii) TOTOX value
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
To a 0.5 g sample of impure NaCl are added 0.784 g of pure AgNO3 (MW = 169.88) crystal. This is in excess of the amount required to ppt. All the Cl as AgCl. After dissolving and filtering out the pptd. AgCl, the filtrate requires 25.50 ml of 0.028M KCNS. What is the percentage of NaCl (MW=58.44) in the sample? A. 55.40 % B. 50.10% C. 45.60% D. 100%
Organic carbon in seawater can be measured by oxidation to CO2 with K2S2O8, followed by gravimetric determina- tion of CO2 trapped by a column of Ascarite. Water weighing 6.234 g produced 2.378 mg of CO2 (FM 44.010). Find ppm carbon in the seawater.
A 0.1475-M solution of Ba(OH)2 was used to titrate the acetic acid (60.05 g/mol) in a dilute aqueous solution. The following results were obtained. (See attached image)(a) Calculate the mean w/v percentage of acetic acid in the sample.(b) Calculate the standard deviation for the results.(c) Calculate the 90% confidence interval for the mean.(d) (d) At the 90% confidence level, could any of the results be discarded?
You are given a container with Na3PO3 that is reportedly contaminated. You are asked by your supervisor to determine the percent purity of that sample in order to know the next measures to be taken by the plant. The following are the procedures that you need to do: a. Dissolve sample weighing 1 g in 35 mL water. b. Prepare solution with 45 mL 3% w/v HgCl2, 30 mL 10% w/v C2H3NaO2 and 10 mL CH3COOH. c. Digest sample then filter then rinse the precipitate that weighs 0.2857 g. d. Compute for the % purity.
Spike recovery and detection limit. Species of arsenic found in drinking water include AsO32 3 (arsenite), AsO32 4 (arsenate), (CH3)2AsO2 2 (dimethylarsinate), and (CH3)AsO22 3 (methylarsonate). Pure water containing no arsenic was spiked with 0.40 mg arsenate/L. Seven replicate determinations gave 0.39, 0.40, 0.38, 0.41, 0.36, 0.35, and 0.39 mg/L.15 Find the mean percent recovery of the spike and the concentration detection limit (mg/L).
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A 100 ml bottle of metronidazole 100 mg/ml suspension is available in your pharmacy. Calculate the volume of this suspension needed to be diluted with cherry syrup to prepare 60 ml of a 4% metronidazole suspension. 1 ml of a 1:1000 epinephrine injection was mixed with 20 ml of 1% lidocaine injection. Calculate the new ratio strength of epinephrine in the admixture. (IGNORE ANY VOLUME CHANGES AFTER ADMIXTURE) Instead of preparing 4 grams of tetracaine hydrochloride 4% gel an 8% gel was compounded by mistake. How many grams of the 8% gel and gel base must be mixed to get 4 grams of a 4% gel? How many milliliters of 70% ethanol and 20% ethanol must be mixed to prepare 500 ml of 30% ethanol? A diphenhydramine elixir contains 12.5 mg drug in one teaspoon. The volume of oral vehicle that is to be added to 100 ml of this elixir to reduce its strength by one half its original strength is; 6. 90 capsules of Liothyronine (T3) 15 micrograms are to be prepared. The formula calls for a 1:10000…
Calculate the retardation factor (Rf) for dissolved Tetrachloroethene contamination given the bulk density of soil is 2.4 gm/cc, fraction organic content (foc) of soil is 0.005, and the Organic Carbon Partition Coefficient (Koc) is the number you look up in the table. HInt: Use Fetter Equation (Koc = Kd /foc to calculate Kd. Group of answer choices 1.4 to 2.7 l/gm 1.08 to 1.2 Cannot be calculated from given information. 3.25 to 4.5 1.05 to 1.2 l/gm
Given the following groundwater analysis at 25 °C: Ca2+: 83.27 mg/L Mg2+: 24.32 mg/L Na+: 18.33 mg/L K+: 2.34 mg/L SO42-: 23.45 mg/L HCO3-: 366.78 mg/L Cl-: 12.50 mg/L pH = 7.8 TDS = 542 mg/L 1) Do a cation-anion balance. 2)Find the ion activity product (IAP) of calcite CaCO3. 3)Compare the IAP of anhydrite with the Ksp of calcite (10-8.4).