128. One method for determining the purity of aspirin (empirical for- mula, C,H,O,) is to hydrolyze it with NaOH solution and then to titrate the remaining NaOH. The reaction of aspirin with NaOH is as follows: C,H,O,(s) + 20H (aq) Aspirin Boil C;H;O; (ag) + C,H,O, (aq) + H,0(1) Salicylate ion 10 min Acetate ion A sample of aspirin with a mass of 1.427 g was boiled in 50.00 mL of 0.500 M NaOH. After the solution was cooled, it took 31.92 mL of 0.289 M HCl to titrate the excess NaOH. Cal- culate the purity of the aspirin. What indicator should be used for this titration? Why?

128. One method for determining the purity of aspirin (empirical for- mula, C,H,O,) is to hydrolyze it with NaOH solution and then to titrate the remaining NaOH. The reaction of aspirin with NaOH is as follows: C,H,O,(s) + 20H (aq) Aspirin Boil C;H;O; (ag) + C,H,O, (aq) + H,0(1) Salicylate ion 10 min Acetate ion A sample of aspirin with a mass of 1.427 g was boiled in 50.00 mL of 0.500 M NaOH. After the solution was cooled, it took 31.92 mL of 0.289 M HCl to titrate the excess NaOH. Cal- culate the purity of the aspirin. What indicator should be used for this titration? Why?

Appl Of Ms Excel In Analytical Chemistry

2nd Edition

ISBN:9781285686691

Author:Crouch

Publisher:Crouch

Chapter3: Statistical Tests With Excel

Section: Chapter Questions

Problem 5P

See similar textbooks

Similar questions

Lead poisoning has been a hazard for centuries. Some scholars believe that the decline of the Roman Empire can be traced, in part, to high levels of lead in water from containers and pipes, and from wine that was stored in leadglazed containers. If we presume that the typical Roman water supply was saturated with lead carbonate, PbCO3 (Ksp = 7.4 1014), how much lead will a Roman ingest in a year if he or she drinks 1 L/day from the container?
The iron content of hemoglobin is determined by destroying the hemoglobin molecule and producing small water-soluble ions and molecules. The iron in the aqueous solution is reduced to iron(II) ion and then titrated against potassium permanganate. In the titration, iron(ll) is oxidized to iron(III) and permanganate is reduced to manganese(II) ion. A 5.00-g sample of hemoglobin requires 32.3 mL of a 0.002100 M solution of potassium permanganate. The reaction with permanganate ion is MnO4(aq)+8H+(aq)+5Fe2+(aq)Mn2+(aq)+5Fe3+(aq)+4H2O What is the mass percent of iron in hemoglobin?
When jump-starting a car with a dead battery, the ground jumper should be attached to a remote part of the engine block. Why?
On Easter Sunday, April 3, 1983, nitric acid spilled from a tank car near downtown Denver, Colorado. The spill was neutralized with sodium carbonate: 2HNO3(aq)+Na2CO3(aq)2NaNO3(aq)+H2O(l)+CO2(g) a. Calculate H for this reaction. Approximately 2.0 104 gal nitric acid was spilled. Assume that the acid was an aqueous solution containing 70.0% HNO3 by mass with a density of 1.42 glcm3. What mass of sodium carbonate was required for complete neutralization of the spill, and what quantity of heat was evolved? (Hf for NaNO3(aq) = 467 kJ/mol) b. According to The Denver Post for April 4, 1983, authorities feared that dangerous air pollution might occur during the neutralization. Considering the magnitude of H, what was their major concern?
Magnesium metal (a component of alloys used in aircraft and a reducing agent used in the production of uranium, titanium, and other active metals) is isolated from sea water by the following sequence of reactions: Mg2+(aq)+Ca(OH)2(aq)Mg(OH)2(s)+Ca2+(aq)Mg(OH)2(s)+2HCl(aq)MgCl2(s)+2H2O(l)MgCl2(l)electrolysisMg(s)+Cl2+Cl2(g) Sea water has a density of 1.026 g/cm3 and contains 1272 parts per million of magnesium a5 Mg2+(aq) by mass. What mass, in kilograms, of Ca(OH)2; is required to precipitate 99.9% of the magnesium in 1.00103 L of sea water?
To determine , by gravimetric analysis, the concentration of barium ions (Ba2+) in a given solution, 25.00cm3 of it are pipetted into a beaker and an excess of dilute sulphuric acid is added to it. The precipitate then obtained (BaSO4) is filtered, dried and weighed. The mass of the precipitate is found to be 1.167g Calculate the concentration of barium ions in the solution? (only 2 decimal places). _________Mol/L
Tartaric acid, H2C4H4O6, is a diprotic acid that naturally occurs in the production of wine. Jose was tasked to find out the acid content in a 100.0 mL wine sample by titrating it with a standardized solution of NaOH. He was able to establish the working concentration of the NaOH solution by using 35.21 mL of it to titrate a primary standard of KHP that weighed 3.001 g. The grams and %w/w of Tartaric acid present in the 100.0 mL wine sample were then determined by titrating a 25.00 mL aliquot using 43.56 mL of the standardized NaOH solution. H2C4H4O6 (aq) + 2NaOH (aq) ↔ Na2C4H4O6 (aq) + 2H2O (l) Assume that the density of the wine sample is 1.000 g/mL MM of KHP = 204.22 g/mol MM of H2C4H4O6 = 150.087 g/mol What is the molar concentration of the prepared NaOH solution?…
The concentration of arsenic in an insecticide can be determined gravimetrically through its precipitation as MgNH4AsO4. After the formation of the precipitate, it must be ignited for total conversion to Mg2As2O7, which is then cooled and weighed. Considering that a sample of 1,627 g of the insecticide produced 106.5 mg of Mg2As2O7, determine the% (m/m) As2O3 in the insecticide. Given the molar masses: Mg2As2O7 = 310.447 g / mol and As2O3 = 197.841 g / mol
Hydrogen peroxide solutions can easily be decomposed by dust, trace amounts of metals or light. It istherefore necessary to periodically determine the purity of the peroxide solutions.This can be done via a redox titration as follows: The density of a particular surgical grade hydrogen peroxide solution is 1.11g.cm-3. Exactly 10 mL of this solution was pipetted and quantitatively transferred, along with a sufficientamount of a dilute sulphuric acid solution, into a 250.00 mL volumetric flask and made up to the mark. A 25.00 mL portion of this diluted solution is pipetted into a conical flask, and titrated with a0.372 M KMnO4 solution. The endpoint of the titration is determined when the colourless solution in the conical flask turns apersistent bright pink due to the presence of excess permanganate ions. The average titration value is 26.20 mL of the KMnO4 solution 1.Determine the percentage of the hydrogen peroxide in the solution sample.2. Naturally occurring manganese…
Choi is fond of carbonated beverages so he crafted his own soda formulation called “Sodalicious.” Ulan, who is a fellow enthusiast, also made her own formulation which she called “Soda Pop!” to challenge his friend Choi. To know which formulation is better, they sought to determine the carbonic acid content of their soda formulations using titration. In the first part of their experiment, a 0.5 Mlabeled NaOH solution was standardized against 0.350 grams of KHP (MW = 204.22 g/mol) primary standard that is 99.6% pure. The titration required 3.16 mL of the NaOH solution to reach the phenolphthalein endpoint. In the second part of their experiment, Choi and Ulan independently prepared their samples by taking 25.0-mL of their soda sample and diluting it to 30.0 mL. Using the same titrant and indicator, Choi’s “Sodalicious” required 1.39 mL of the standardized titrant to reach the endpoint, while Ulan’s “Soda Pop!” required 0.926 mL of the same titrant to reach the endpoint. A. What is the…
Choi is fond of carbonated beverages so he crafted his own soda formulation called “Sodalicious.” Ulan, who is a fellow enthusiast, also made her own formulation which she called “Soda Pop!” to challenge his friend Choi. To know which formulation is better, they sought to determine the carbonic acid content of their soda formulations using titration. In the first part of their experiment, a 0.5 Mlabeled NaOH solution was standardized against 0.350 grams of KHP (MW = 204.22 g/mol) primary standard that is 99.6% pure. The titration required 3.16 mL of the NaOH solution to reach the phenolphthalein endpoint. In the second part of their experiment, Choi and Ulan independently prepared their samples by taking 25.0-mL of their soda sample and diluting it to 30.0 mL. Using the same titrant and indicator, Choi’s “Sodalicious” required 1.39 mL of the standardized titrant to reach the endpoint, while Ulan’s “Soda Pop!” required 0.926 mL of the same titrant to reach the endpoint. D. Calculate…
You are required to standardize a dilute solution of sulphuric acid, and undertake the following steps:(i) 4.805 g of solid sodium tetraborate (Na2B4O7) are added to a 250 mL volumetric flask, and the solution made up to the mark with distilled water.(ii) 25.00 mL aliquots of the stock solution from (i) are transferred to conical flasks, for titration against the sulphuric acid solution in the burette.(iii) You perform titrations using two different indicators: bromocresol green, and phenolphthalein.With bromocresol green, the average titre volume is 22.50 cm3, while with phenolphthalein, the average volume is 9.50 cm3.(a) Write the balanced equation for the reaction between Na2B4O7 and sulphuric acid