To the sample, add approximately 50 mL of laboratory water and stir continuously with a glass stirring rod for about two minutes. Determine the empirical formula of naphthalene. 2.5. Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. Given: mass of sample and mass of combustion products M 00 Local naphthalene mass flux, kg/s-m2. A 3.000-mg sample of naphthalene burns to give 10.3 mg of CO 2. All operations required to test a sample or to standardize the 1341 Plain Jacket Calorimeter should proceed step-wise in the following manner: 1. Pure Benzene freezes at 5.51C and has a Kf = 5.12C kg/mol. Determine the empirical formula of naphthalene. 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. v, Density of naphthalene in . Determine the empirical formula of naphthalene. . Many organic solvents, like ether and dichloromethane . Determine its empirical and molecular formulas. . 2. Determine the empirical formula of naphthalene. Determine the empirical formula of naphthalene. and potassium chloride (KCl) has a total mass of 4.000g. Spot 3: A few crystals of naphthalene product in 1 mL ethyl acetate. Krause, in Studies in Surface Science and Catalysis, 2001 3.3 Naphthalene and Tetralin Conversion. It is best known as the main ingredient of traditional mothballs % by mass of naphthalene in original sample. Experiment: We obtained 3.1 grams of the benzoic acid, aniline, and naphthalene mixture. Normalize to obtain the empirical formula and then use the molecular mass to determine the actual molecular formula. 17 Naphthalene is considered low in toxicity by . The freezing point of naphthalene is 80.2C. Prepare the sample and charge the oxygen combustion vessel as described in Instruction Manual No. This mixture was then to be separated using 5% HCl, 5% NaOH, 6M NaOH, and 6M HCl. A solution containing a known mass of solute per mass of solvent is prepared and its freezing point is measured. 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). Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. Determine its empirical formula. Naphthalene conversion (naphthalene hydrogenated to tetralin, octalins and decalins) varied from 4 to 96%. Determine the empirical formula of naphthalene. 1) Will weighing the collected (scraped) naphthalene % by mass of naphthalene in original sample. T f,solution T f,solvent = T f = K f . That is: mass of oxygen = 1.00 g - (0.409 g + 0.046 g) = 1.00 g - 0.455 g = 0.545 g. 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. The vapor pressure of pure hexane at . chem 121. 4 The Chemical Abstracts Service (CAS) registry number is 91-20-3. The freezing point of the solution was determined and found equal to 78.1C. a) calculate % by mass of naphthalene, 3-nitroaniline and benzoic acid in original sample 1. b) A: 1)a. [13] As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings. 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. 1. Calculate the percent composition for each of the components. 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. b. Naphthalene is a bicyclic aromatic hydrocarbon derived from coal tar or crude oil. 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. 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

The naphthalene yield was much lower, . 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 19 Researchers determined an LD 50 of 353.6 mg/kg for female CD-1 mice based on an 8-day oral exposure. (Sub)clinical endpoint measures included nasal endoscopy, smell sensitivity, self-reported work-related complaints and the intensity of naphthalene odor and irritation. 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. Subtract to find the mass of NaCl in the original mixture. 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). Given: mass of sample and mass of combustion products C_10H_8 Assuming that is a mass amount, divide each proportion by the atomic weight of the component. Naphthalene (NAP) has received particular attention due to its impact on the environment and human health, mandating its removal from water systems. Naphthalene is an organic compound with formula C 10 H 8.It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. 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 extracted naphthalene/hexane samples were analyzed by gas chromatography equipped with flame ionization detector (GC-FID). CHROMATOGRAPHY is the process of separating a mixture by the . You may rinse the solid NaCl residue down the drain. 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. A 10 ml volume of a synthetic sample was extracted with 10 ml of dichloromethane in a 30 ml vial; the layers were allowed to separate.Prior to SPE work, 2-4 ml of the organic layer was removed and stored in a sealed glass vial at 4 C.The extraction of a river water sample was carried out essentially according to . Determine the percent by mass of each component on your mixture using the following formula: mass of component A % of component A x 100% mass of original sample ring stand 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. In this work, the abatement of NAP in the aqueous phase was achieved using persulfate (PS) activated by Fe (III) and monochromatic LED light at a natural pH. The reaction taking place is. Elemental analysis can be used to determine the amounts of substances in a mixture. All samples showed concentrations above the limit of quantification, except for samples 2 and 3 of the outdoor air. Naphthalene is soluble in methanol and insoluble in water. The number of moles of solute can be determined by rearranging Eq. Linear regressions passing the original point were applied for all the sorbents under the range of naphthalene concentration (1 ppm-40 ppm). Discussion: During World War 2, one of the major problems scientists faced . 3 Its International Union of Pure and Applied Chemistry (IUPAC) name is naphthalene. This paper is intended to be an introductory text on the naphthalene sublimation technique. 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. 2.

Homework Statement. The use of mass spectrometry (MS) is becoming widespread and rather routine in all levels of industry, government, and academia. Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. Dolomitic limestone is a mixture of CaCO3 and MgCO3. [] 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. A student completed the experiment but found that the total amount of material recovered weighed more than the original sample. The air stream was combusted, and a flame ionization . . 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. Not only was it evident that the impurities had been removed due to the color of the resultant Naphthalene, but it could also be seen in the difference between the starting mass and the mass retrieved. Naphthalene appears to be more toxic to mice than rats. 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 0.500 g sample of naphthalene (C10H8) is burned in a bomb calorimeter containing 650 . Local and average mass transfer coefficient, m/s. Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. Let mixture stand for a few minutes to allow the undissolved components settle to the bottom of the mixture. A 1.60 g sample of a mixture of naphthalene, C10H8, and anthracene, C14H10, is dissolved in 20.0 g benzene, C6H6. You dissolve 0.4500 g of impure potassium chloride in water and add an excess of silver nitrate. Calculate the mass of NaHCO3 present in the original mixture. What are the empirical and molecular formulas of the compound? These data were obtained by passing air over a sample of the sub-stance in a tube. Follow your professors instructions. C5H4 C10H8 C2H3 None of these The original mass of the 50:50 mixture measured was 2.042g, and assuming it is truly 50:50, it can be anticipated that the mass of both naphthalene and benzoic acid was 1.021g. Repeat three additional times. This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here! 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. This corresponds to a naphthalene hydrogenation rate of 1-2410 3 mol/(kg cat s). . The percent yield was not 100%, which proved that something from the original sample had been removed. Mass of dish #1 plus NaCl and SiO 2 _____ 5. From this we must calculate the mass percentage of solute. 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.

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. 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. Subtract this number and the mass of the salt from the original total mass will help you find the mass of the sand. A package of freshly picked sweet peas has a mass of 454 g (1 lb.). Naphthalene, the active ingredient in one variety of mothballs, is an organic compound that contains carbon and hydrogen only. Mass of original sample _____ 4. Naphthalene and 2-naphthol are two naphthalene derivatives, which play important roles in the chemical and pharmaceutical industries. The freezing point of the solution is 2.81oC. 1,2 It is an insecticide that is also used as a repellent.

The sample should be transferred to a beaker. Mass of dish #1 plus dry SiO . Iodine (I2), naphthalene (C10H8, mothballs), ammonium chloride (NH4Cl) and dry ice (solid CO2) are some substances which sublime. Webinars; Posters; Hubs; . The same explanations hold true for . The mass of water evaporated is obtained by subtracting the mass of the anhydrous solid from the mass of the original hydrate (\ref{3}): . Chemistry. 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. 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 . Naphthalene | C10H8 | CID 931 - structure, chemical names, physical and chemical properties, classification, patents, literature, biological activities, safety . Solution: The chemical equation is KCl (aq)+AgNO3(aq) KNO3(aq) +AgCl (s) Determine the composition (mass percentage) of naphthalene-anthracene mixture?" Given: mass of sample and mass of combustion products 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. . Keywords - Journal. A 0.573g sample of a nonvolatile solute is added to 15.6g of napthalene and the mixture warmed until melted. Need some help here: 1. Naphthalene Naphthalene is an organic compound with formula C 10 H 8. 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. A student found that the mass of the naphthalene collected was less than the mass determined by difference. . tt. the purity of the naphthalene fraction changes over the course of the extraction. Created by Sal Khan. Freezing point depression provides a convenient way to determine the molar mass of an unknown substance. Calculate the change in mass for each sample. 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. r Radial coordinate, m. Sh;Sh Local and average Sherwood number. 3 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. 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. A 1.00 g sample of naphthalene (C10H8) contains 0.562 g of hydrogen. Sample ID #74 Mass of Vial with sample 12.00g Mass of Empty Vial 10.00g Mass of Sample 2.00g Mass of 100 mL round-bottom flask 67 . SPQ2.B (LO) , SPQ2.B.1 (EK) Transcript. Methods of pesticide analyses have been largely driven by the food industry [1-3].In their comprehensive paper of 2000, Filion et al. Ba2+(aq) + SO42-(aq) ( BaSO4(s) 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. We did a lab separating out the components of a mixture. The percentage yield for this experiment was 88.314%. 205M. What are the empirical and molecular formulas of the compound? used to weigh the beaker and watch glass. Extraction of markers (NAPF) from synthetic water and lake water samples. 82) A sample of 0.6760 g of an unknown compound containing barium ions (Ba2+) is dissolved in water and treated with excess Na2SO4. Nearest whole multiple is 5, resulting in ratio of 6:5.

7. How much heat is needed to convert 10g ice to 10g water vapor? 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 reaction was carried out in a slurry batch reactor using goethite as the Fe (III) source. View Calculation.pdf from CHM chm1321 at University of Ottawa. 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. When the reaction ends, pour out the water and weighed the mass of the mixture on the digital scale. Attempt to get samples within 100 mg of the weight of the original sample. When this sample is dissolved . Add some of this hot solvent to It will dissolve in a hot mixture of 3:1 methanol:water but is less soluble when this mixture is cold. 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. As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings. A package of freshly picked sweet peas has a mass of 454 g (1 lb.). "A 1.60 g sample of a mixture of naphtalene, C10H8. 2) Calculate the mass percent of NaHCO3 in the uknown mixture . The makeup of that 88.314% is divided between naphthalene at 4.550%, NaCl at 39.368%, and sea sand at 44.397%. Chemistry questions and answers. Methods. The freezing point of the solution is 2.81C. -naphthalene as matrix Authors. Each step produced an organic layer as well as an aqueous layer. Plan We can calculate the mass percentage by using Equation 13.5. What was the % by mass of CaCO3 in the original sample? Upload a picture of your drawn separation scheme for benzoic acid from the . chemistry. The percent composition for each component is: 16.5g carbohydrates / 130.g x 100 = 12.7% carbohydrates, 9.7g sugar / 130.g peas x 100 = 7.5% sugars, 8.1g dietary fiber / 130.g peas x 100 = 6.2% dietary fibers, 4.4g protein / 130.g peas x 100 = 3.4% protein, Fill the calorimeter bucket by first taring the dry bucket on a solution or trip balance . Plate A: Spot 1: A few crystals, ~0.001g/mL, benzoic acid product in 1 mL ethyl acetate.