A study using CD-1 mice identified an acute oral LD 50 of 533 mg/kg in males and 710 mg/kg in females. The peas were freeze dried and the . The peas were freeze dried and the . After the extraction and recrystallization, 0.73g of benzoic acid and 0.502g of naphthalene were recovered. . A simple and sensitive method for the simultaneous analysis of naphthalene, fluorene, and anthracene in whole blood was developed using headspace-solid-phase microextraction (SPME) and GC/MS. . Subtract this number and the mass of the salt from the original total mass will help you find the mass of the sand. 6-C . Iodine (I2), naphthalene (C10H8, mothballs), ammonium chloride (NH4Cl) and dry ice (solid CO2) are some substances which sublime. 7. C5H4 C10H8 C2H3 None of these tt. Plan We can calculate the mass percentage by using Equation 13.5. The reaction taking place is. Discussion: During World War 2, one of the major problems scientists faced . 82) A sample of 0.6760 g of an unknown compound containing barium ions (Ba2+) is dissolved in water and treated with excess Na2SO4. I need the correct answer please Mass of the original sample of mixture (g) 1.537 Mass of recovered naphthalene (9) 0.461 Mass of recovered 3-nitroaniline (g) 0.507 Mass of recovered benzoic acid (g) Q&A. Attempt to get samples within 100 mg of the weight of the original sample. A solution containing a known mass of solute per mass of solvent is prepared and its freezing point is measured. We did a lab separating out the components of a mixture. Need some help here: 1. and potassium chloride (KCl) has a total mass of 4.000g. and anthracene, c14H10 is dissolveed in 20.0g of benzene, C6H6. What is the mass percent of carbon in the compound . Mass of dish #1 plus NaCl and SiO 2 _____ 5. Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. Elemental analysis can be used to determine the amounts of substances in a mixture. Naphthalene Naphthalene is an organic compound with formula C 10 H 8. Mass of the original sample of mixture (g) 1.537 Mass of recovered naphthalene (9) 0.461 Mass of recovered 3-nitroaniline (g) 0.507 Mass of recovered benzoic acid (g) 0.507 (12pts) Calculations (3/3pts) % by mass of naphthalene in original sample 30.0 V (0/3pts) % by mass of 3-nitroaniline in original sample 30.0 (-3 pts) Incorrect. What are the empirical and molecular formulas of the compound? The mass of the solution is the sum of . When a 1.00 grams sampleof this limestone is decomposed by heating, 268 cm3 of CO2 (g) is produced measured at 750. torr and 20C. After drying the flask was re-massed and the mass of naphthalene was determined. A 3.000-mg sample of naphthalene burns to give 10.3 mg of CO2. Spot 3: A few crystals of naphthalene product in 1 mL ethyl acetate. By the end, we should have had the separated benzoic acid, aniline, and naphthalene. Record exact mass. The makeup of that 88.314% is divided between naphthalene at 4.550%, NaCl at 39.368%, and sea sand at 44.397%. Chemistry. Methods of pesticide analyses have been largely driven by the food industry [1-3].In their comprehensive paper of 2000, Filion et al. The sample should be transferred to a beaker. A 0.573g sample of a nonvolatile solute is added to 15.6g of napthalene and the mixture warmed until melted. Spot 2: The sample of liquid mixture taken before the rotary evaporation/or re-crystallization. 7. From this we must calculate the mass percentage of solute. The vapor pressure of pure hexane at . Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. The highest concentrations . Naphthalene (C ioH 8) is employed in the mass transfer experiments because of some of its properties, such as the fact that it sublimes at room temperature, its low toxicity, and its good casting and machining properties. A 1.60 g sample of a mixture of naphthalene, C10H8, and anthracene, C14H10, is dissolved in 20.0 g benzene, C6H6. Naphthalene (NAP) has received particular attention due to its impact on the environment and human health, mandating its removal from water systems. Ba2+(aq) + SO42-(aq) ( BaSO4(s) The aim of this study was to evaluate the impact of biofield energy treatment on the isotopic abundance of 13 C/ 12 C or 2 H/ 1 H and 18 O/ 16 O in naphthalene and 2-naphthol using gas chromatography-mass spectrometry (GC-MS).

Determine its empirical and molecular formulas. Given: mass of sample and mass of combustion products A solution contains naphthalene(C10H8) dissolved in hexane (C6H14) at a concentration of 14.52 % naphthalene by mass.Calculate the vapor pressure at 25 degrees C of hexane above the solution. the purity of the naphthalene fraction changes over the course of the extraction. Fill the calorimeter bucket by first taring the dry bucket on a solution or trip balance . Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. A student completed the experiment but found that the total amount of material recovered weighed more than the original sample.

View Calculation.pdf from CHM chm1321 at University of Ottawa. Weigh a clean and dry 250-mL beaker (Beaker #2). This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here! Lab 4 Separation of Benzoic Acid, 3-Nitroaniline, and Naphthalene Objectives Separate organic compounds based on functional groups Use pH changes to separate compounds Background Separations of Immiscible Liquids Throughout organic experiments, multiple different solvents get used, such as a variety of organic solvents and water. . A 1.60 g sample of a mixture of naphthalene, C10H8, and anthracene, C14H10, is dissolved in 20.0 g benzene, C6H6. Chemistry questions and answers. mass of oxygen = mass of sample - (mass of carbon plus mass of hydrogen) Since we burned 1.00 g of our sample, it follows that we can calculate the mass of oxygen by subtracting the combined masses of C and O from the mass of sample. . Using the technique of weighing by difference, weigh out a 0.7 g sample of NaCl. Created by Sal Khan. 4 The Chemical Abstracts Service (CAS) registry number is 91-20-3. v, Density of naphthalene in . Naphthalene is soluble in methanol and insoluble in water. [13] As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings. It will dissolve in a hot mixture of 3:1 methanol:water but is less soluble when this mixture is cold. Determine the composition (mass percentage) of naphthalene-anthracene mixture?" . Data Collection Mass of the original sample of mixture (g) 1.558 Mass of recovered naphthalene (g) 0.483 Mass of recovered 3-nitroaniline (g) 0.499 Mass of recovered benzoic acid (g) 0.467 Calculations: a. Q: % by mass of naphthalene in original sample % by mass of 3-nitroaniline in original sample % by mass A: Given mass of the original sample of mixture (g)= 1.547 mass of recovered naphthalene (g) = 0.511 To the sample, add approximately 50 mL of laboratory water and stir continuously with a glass stirring rod for about two minutes. % by mass of naphthalene in original sample. The naphthalene yield was much lower, . 93.91/12 = 7.83 relative moles of carbon 6.29/1 = 6.29 relative moles of hydrogen Ratio of C:H is 7.83:6.29 or 1.2. Determine the empirical formula of naphthalene. Given: mass of sample and mass of combustion products Determine its empirical formula. Add some of this hot solvent to A.O.I. Nearest whole multiple is 5, resulting in ratio of 6:5. C_10H_8 Assuming that is a mass amount, divide each proportion by the atomic weight of the component. The dermal LD 50 was determined to be greater than 2000 mg/kg in rabbits. A student decides to change the procedure for a lab, attempting to determine the mass of naphthalene in the sample by collecting the solid scrapings from the evaporating dish and weighing them directly (as opposed to weighing the beaker before and after sublimation). Do not stir at this time. This paper is intended to be an introductory text on the naphthalene sublimation technique. TALANTA Volume 85, Issue 1, Pages 345 . 2.5. You get 0.8402 g of insoluble silver chloride. (Sub)clinical endpoint measures included nasal endoscopy, smell sensitivity, self-reported work-related complaints and the intensity of naphthalene odor and irritation. Methods. A substance is classified as efflorescent if its mass decreases by 0.005 g or more; and it is classified as hygroscopic if its mass increases by 0.005 g or more. It is best known as the main ingredient of traditional mothballs 2) Calculate the mass percent of NaHCO3 in the uknown mixture . Determine the empirical formula of naphthalene. Complete combustion of a 20.10 mg sample of naphthalene in oxygen yielded 69.00 mg of CO 2 and 11.30 mg of H 2 O. Calculations Total mass of original mixture- 1.02g Mass of sand: 0.65 g Mass of salt- 0.233g Mass of calcium carbonate: 0.137g What was the % by mass of CaCO3 in the original sample? 19 Researchers determined an LD 50 of 353.6 mg/kg for female CD-1 mice based on an 8-day oral exposure. After a second heating cycle, the mass of the sample and the dish is 14.78 g. The student stops the heat/cool/weigh cycle after the second time. Determine the empirical formula of naphthalene. Calculate the percent by mass of KCl in the original sample. All operations required to test a sample or to standardize the 1341 Plain Jacket Calorimeter should proceed step-wise in the following manner: 1. c. % by mass of benzoic acid in original sample. A 0.500 g sample of naphthalene (C10H8) is burned in a bomb calorimeter containing 650 . A 0.025-g sample of a compound composed of boron and hydrogen, with a molecular mass of ~28 amu, burns spontaneously when exposed to air, producing 0.063 g of B 2 O 3. Determine the empirical formula of naphthalene. b. Determine the empirical formula of naphthalene. The freezing point of the solution is 2.81oC. . For example, if elemental analysis tells us that a potassium supplement contains 22% K by mass, and we know that the K is present as KCl, we can calculate the grams of KCl in the supplement. The percent yield was not 100%, which proved that something from the original sample had been removed. 205M. The use of mass spectrometry (MS) is becoming widespread and rather routine in all levels of industry, government, and academia. Calculation % by mass of naphthalene in original sample: (0.632 g/ 2.039 g) x 100 = 30.9955861% % by mass of 3-nitroaniline in original A 3.000-mg sample of naphthalene burns to give 10.3 mg of CO 2. Let mixture stand for a few minutes to allow the undissolved components settle to the bottom of the mixture. Upload a picture of your drawn separation scheme for benzoic acid from the . The vapor pressure of pure hexane at chem 121 We did a lab separating out the components of a mixture. Dermal. A 3.000-mg sample of naphthalene burns to give 10.3 mg of CO 2. Naphthalene | C10H8 | CID 931 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety . 17 Naphthalene is considered low in toxicity by . Complete combustion of a 20.10 mg sample of naphthalene in oxygen yielded 69.00 mg of CO 2 and 11.30 mg of H 2 O. The percent yield was found by dividing the mass of the recovered solids by the mass of the mixture, then multiplying the answer by 100. Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. The mass of water evaporated is obtained by subtracting the mass of the anhydrous solid from the mass of the original hydrate (\ref{3}): . Experiment: We obtained 3.1 grams of the benzoic acid, aniline, and naphthalene mixture. Dolomitic limestone is a mixture of CaCO3 and MgCO3. 20. Pure Benzene freezes at 5.51C and has a Kf = 5.12C kg/mol. Record the mass and number or letter of the unknown on the data sheet and place the unknown in the test tube containing your original sample of naphthalene. Calculate the mass of NaHCO3 present in the original mixture. % by mass of 3-nitroaniline in original sample. A 0.5 g whole blood sample, 5 microL naphthalene, fluorene, and anthracene (50 microg/mL) as spiked standards, and 0.5 mL sodium hydroxide were placed . An additional experiment carried out with very low catalyst loading led to a low . A student found that the mass of the naphthalene collected was less than the mass determined by difference. CHROMATOGRAPHY is the process of separating a mixture by the . chemistry. The principal component of mothballs is naphthalene, a compound with a molecular mass of about 130 amu, containing only carbon and hydrogen. Plate A: Spot 1: A few crystals, ~0.001g/mL, benzoic acid product in 1 mL ethyl acetate. . These data were obtained by passing air over a sample of the sub-stance in a tube. A solution contains naphthalene (C10H8) dissolved in hexane (C6H14) at a concentration of 14.52 % naphthalene by mass.Calculate the vapor pressure at 25 degrees C of hexane above the solution. Given: mass of sample and mass of combustion products Many organic solvents, like ether and dichloromethane . Each step produced an organic layer as well as an aqueous layer. The freezing point of the solution is 2.81C. A 0.025-g sample of a compound composed of boron and hydrogen, with a molecular mass of ~28 amu, burns spontaneously when exposed to air, producing 0.063 g of B 2 O 3. Mass of the original sample of mixture (g) 1.547 Mass of recovered naphthalene (g) 0.511 Mass of recovered 3-nitroaniline (g) 0.480 Mass of recovered benzoic acid (g) 0.472 % by mass of naphthalene in original sample % by mass of 3-nitroaniline in original sample % by mass of benzoic acid in original sample Total percent recovered. 2. Thirtynine healthy and non-smoking male employees with either moderate (n = 22) or high (n = 17) exposure to naphthalene were compared to 22 male employees from the same plants with no or only rare exposure to naphthalene. Mass of dish #1 plus dry SiO . The freezing point of naphthalene is 80.2C. Complete combustion of a 20.10 mg sample of naphthalene in oxygen yielded 69.00 mg of CO 2 and 11.30 mg of H 2 O. (3pts) % by mass of naphthalene in original sample (3pts) % by mass of 3-nitroaniline in original sample (3pts) % by mass of benzoic acid in original sample (3pts) Total percent recovered Mass of the original sample of mixture (9) Mass of recovered naphthalene (9) Mass of recovered 3-nitroaniline (9) Mass of . Sample Exercise 13.3 Converting Units of Temperature Solution (a) Analyze We are given the number of grams of solute (13.5 g) and the number of grams of solvent (0.100 kg = 100 g). Normalize to obtain the empirical formula and then use the molecular mass to determine the actual molecular formula. Coupled with chromatographic methods, this powerful instrumental technique can be used to elucidate the composition of a complex sample and definitively identify constituents while offering the benefits of high-precision quantitative analysis and low detection limits. Determine its empirical and molecular formulas. Naphthalene and 2-naphthol are two naphthalene derivatives, which play important roles in the chemical and pharmaceutical industries. The number of moles of solute can be determined by rearranging Eq. If the mass of the BaSO4 precipitate formed is 0.4105 g, what is the percent by mass of Ba in the original unknown compound? To recrystallize the naphthalene, heat about 50 mL of the 3:1 methanol:water mixture almost to the boiling point on a steam bath (see p. 78 in LTOC). 3 Its International Union of Pure and Applied Chemistry (IUPAC) name is naphthalene. A 1.00 g sample of naphthalene (C10H8) contains 0.562 g of hydrogen. Solution for 1. a) calculate % by mass of naphthalene, 3-nitroaniline and benzoic acid in original sample 1. b) calculate total mass of three recovered Webinars; Posters; Hubs; . The naphthalene was the scraped into a vial with no cap and left to stand and dry for a week before determining the melting point. Given: mass of sample and mass of combustion products M 00 Local naphthalene mass flux, kg/s-m2. Naphthalene conversion (naphthalene hydrogenated to tetralin, octalins and decalins) varied from 4 to 96%. This mixture was then to be separated using 5% HCl, 5% NaOH, 6M NaOH, and 6M HCl. used to weigh the beaker and watch glass. An 887.0 mg sample of a mixture containing only NaCl and KCl is dissolved in water, and excess AgNO3 is added to yield 1.913 g of AgCl. . a) calculate % by mass of naphthalene, 3-nitroaniline and benzoic acid in original sample 1. b) A: 1)a. Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. Rautanen, . [] screened fruit and vegetable samples for 251 known pesticides by extracting pulp with solvent before clean-up on solid phase extraction cartridges.The final extract was pre-concentrated and analysed by GC-MS or LC-fluorescence. Keywords - Journal. Mass of original sample _____ 4. 3. . Linear regressions passing the original point were applied for all the sorbents under the range of naphthalene concentration (1 ppm-40 ppm). Naphthalene appears to be more toxic to mice than rats. Mass of the original sample of mixture (g) 1.571 Mass of recovered naphthalene (g) 0.518 Mass of recovered 3-nitroaniline (g) 0.487 Mass of recovered benzoic acid (g) 0.505 Required: a. 3 2. The reaction was carried out in a slurry batch reactor using goethite as the Fe (III) source. The molecular mass of naphthalene = 128.17 gm/mol The molecular mass of 3-nitro aniline = This corresponds to a naphthalene hydrogenation rate of 1-2410 3 mol/(kg cat s).