Part V. A 1.0-mL volume of 0.0020 M H2SO3 is added to a mixture of 6 drops of 0.010 MHIO3, 14 drops of deionized water, and 1 drop of starch solution. A color change in the reaction mixture occurred after 56 seconds. mol HIO3 total volume (L) after the mixing but before any reaction occurs (at time = 0). Assuming 20 drops per milliliter for all solutions, the initial molar concentration of HIO3 is mol H2S03/L The rate of the reaction is measured by the disappearance of H2503. For the reaction mixture in this question, the reaction rate is sec

Part V. A 1.0-mL volume of 0.0020 M H2SO3 is added to a mixture of 6 drops of 0.010 MHIO3, 14 drops of deionized water, and 1 drop of starch solution. A color change in the reaction mixture occurred after 56 seconds. mol HIO3 total volume (L) after the mixing but before any reaction occurs (at time = 0). Assuming 20 drops per milliliter for all solutions, the initial molar concentration of HIO3 is mol H2S03/L The rate of the reaction is measured by the disappearance of H2503. For the reaction mixture in this question, the reaction rate is sec

Macroscale and Microscale Organic Experiments

7th Edition

ISBN:9781305577190

Author:Kenneth L. Williamson, Katherine M. Masters

Publisher:Kenneth L. Williamson, Katherine M. Masters

Chapter7: Extraction

Section: Chapter Questions

Problem 1Q

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A Flask containing 10ml of 0.010 M KI, 10ml of 0.0010M Na2S2O3, and 10ml H2O are mixed with another flask containing 10ml of 0.040M KBrO3, 10ml of 0.10M HCl and 3 drops of starch to create a reaction. This reaction is repeated in 4 trials at different temperatures. The first trial at 20C, the second at 43C, the third at 33C and the 4th at 6C. We take note of when this reaction goes from a clear solution to a blue color and time it. The first trial took 191s, the second took 37s, the third took 81s and the 4th took 557s. We are given the Observed rates of all 4 trials and are required to find the In(Rate) as well as the 1/Temp reciprocal k using the Arrhenius equation. Trial 1 Rate = 5.24*10^-7 Trial 2 Rate = 2.70*10^-6 Trial 3 Rate = 1.24*10^-6 Trial 4 Rate = 1.80*10^-7
19- A 25 mL liquid bleach sample is diluted with water to 1000 mL in a bubble gel. 25 mL of the diluted sample is transferred to the flask with a pipette, excess KI is added to it, and thus OCl- ion turns into Cl- ion and I2 is formed. The released iodine is titrated with 0.09892 M Na2S2O3 using the starch reagent, and 8.96 mL is required for the endpoint. Find the % NaOCl (w/v; w/v) in the bleach sample. (Na=23 g/mol, O= 16 g/mol, Cl = 35,44 g/mol)
1.063 g of p-acetamidophenol was measured out into a 50 mL round bottom flask along with 8 mL of 1M NaOH in ethanol and a stir bar. This mixture was heated at reflux for 15 min. It was allowed to cool and then 0.80 mL of bromoethane was added to the reaction. The mixture was then heated at reflux for another 15 min. After heating, the solution was poured onto a mixture of ice and water and further cooled on ice and then the solid was collected by vacuum filtration. This solid was then recrystallized from ethanol and water. The final mass of the purified phenacetin was 0.42250 g and it had a melting point of 127 - 130 C. The TLC plate shows (from left to right) pure p-acetamidophenol, the reaction mixture before pouring it on ice/water, phenacetin after recrystallization. The solvent used was a mixture of 80% ethyl acetate and 20% heptane with 0.5% acetic acid added. QUESTION: Using the given TLC plate can you describe the results and what does the TCL plate tell about the purity?
Make a schematic diagram for the procedure below: B. % SO3 determination Dry the soluble sulfate sample at 100° C for 1-2 hours, and cool in desiccator. Weigh out 0.5 – 0.7 g (± 0.3 mg) duplicates sample. Transfer to 400-mL beakers. Dissolve each in 200 mL of dist. H2O + 4 mL of 6 m HCl. Precipitant is prepared by dissolving 1.3 g BaCl2 ∙ H2O in 100 mL water. Filter if solution is not perfectly clear. Heat the BaCl2 solution and sulfate sample solution nearly to boiling, and then add the entire amount to the HOT sulfate sample solution while stirring vigorously. Wash stirring rod with distilled water and include washings in your final mixture. Digest by letting stand 1-2 hours. Overnight standing is acceptable. Filter through an ash less filter paper of fine porosity (Whatman no. 42). Slowly pour the supernatant liquid through the filter paper.
1,4‐Dimethoxybenzene (0.642 g) was dissolved in 2.0 mL acetic acid in a 25 mL Erlenmeyer flask using heat from a hot plate. Once the solid dissolved, 1.0 mL tert‐ butanol was added, and the reaction mixture was cooled in an ice bath. Then 2.0 mL concentrated sulfuric acid was added in 2‐3 drop portions,stirring the mixture after each aliquot. After the addition, the flask was removed from the ice bath and allowed to sit at room temperature for 15 minutes. Then 1.0 mL water was added dropwise to dilute the acid and the reaction mixture was added to 40 mL cold water in a 100 mL beaker. The solid was vacuum filtered and washed with 5 mL cold water, giving 52 g filtrate. The product wasrecrystallized from 4.5 mL methanol, yielding 0.317 g purified 1,4‐di‐tert‐butyl‐2,5‐dimethoxy benzene (27.2% yield). What is the atom economy, e-factor, and effective mass yield?
1. From 17M glacial acetic acid, how would you perform serial dilution to prepare 1.0 M, 0.50 M, and 0.25 M acetic acid solutions? 2. From 0.50 M NaOH solution, how would you prepare (by dilution) 200 mL of 0.1 M NaOH solution?
Lead nitrate Stock Solution— Dissolve 159.8 mg of lead nitrate in 100 mL of water to which has been added 1 mL of nitric acid, then dilute with water to 1000 mL. Standard Lead Solution— On the day of use, dilute 10.0 mL of Lead Nitrate Stock Solution with water to 100.0 mL. Each mL of Standard Lead Solution contains how many µg of lead? Standard Preparation— Into a 50-mL color-comparison tube pipet 2 mL of Standard Lead Solution, and dilute with water to 40 mL, and mix. Test Preparation— Into a 50-mL color-comparison tube dissolve 1.0g ascorbic acid (mol wt 176.12) in 25 mL of water, dilute with water to 40 mL, and mix. Procedure— To each of the two tubes containing the Standard Preparation, the Test Preparation, add 2 mL of pH 3.5 Acetate Buffer, then add 1.2 mL of thioacetamide–glycerin base TS, dilute with water to 50 mL. Mix, allow to stand for 2 minutes, and view downward over a white surface. The color of the solution from the Test Preparation is not darker than that of the…
Please type all of the parts to this question occordingly to the instructions. Here is an example of a formal procedure based off of the experiment presented in Mohrig:Sodium hydroxide (4.6 g) was dissolved in water (25 mL). This solution was added to a 100 mL round bottom flask along with methyl salicylate (2.0 mL) and a stir bar. The mixture was heated at reflux for 15 min and then progressively cooled to 5 °C. The solution was acidified with 3M sulfuric acid (15-20 mL), and the resulting solid was collected by vacuum filtration. The crude salicylic acid was recrystallized from water to yield ???? g of final solid. The melting point and IR were taken to assess purity. Calculate the molarity of the solution of sodium hydroxide that is used.a. M = b. If the original procedure is the base scale (100%), how far are we scaling down the reaction when using 0.75 mL of methyl salicylate? (Example: the original uses 2.0 mL, if we were to use 1.0 mL, we would be scaling the reaction down…
Accurately weigh out about 6g copper(ii) sulfate crystals into a weighing boat. Use the copper(ii) sulfate crystals to make up 250cm3 of standardized copper (ii) sulfate solution Pipette 25cm3 of this solution into a conical flask Add 1.5g potassium iodide and swirl thoroughly Titrate this solution with standard 0.1 moldm-3 Na2S2O3 in a burette. When the iodine color fades, add 1 cm3 starch indicator. Use your titration data below to calculate the percentage by mass of copper in the copper(ii) sulfate crystals.
What is the total amount of compound you can recover after the first recrystallization of 5g impure N-Bromo succinimide (ca. 5% impurity) if you used 30 mL of water. (NBS solubility in hot water:2g/10mL and cold water 0.25g/10mL).
5.0 mL of 1-butanol was mixed with 10 mL of HCl. The reaction was put on an ice bath and 4 mL of concentrated sulfuric acid was added. This mixture was refluxed for 45 min and then the product was co-distilled with water using a simple distillation apparatus. Water and the product are immiscible. 1-butanol has a molar mass of 74.12 g/mol, a density of 0.810 g/mL, and a boiling point of 118 C. The product has a molar mass of 92.57 g/mol, a density of 0.880 g/mL, and a boiling point of 78 C. What is the nucleophile in this reaction? What is the role of H2SO4 in this reaction? Calculate the theoretical yield for this reaction. Give your answer in grams. Select the following statements that can be said about the reaction shown.
0.641 g of a semi-synthetic alkaloid was dissolved in 25 ml of 1% w/v acetic acid and wasanalysed directly by HPLC. The solution was found to contain 1.42 mg/100 ml of an impurity.What is the level of impurity in % w/w and ppm? Calculate the pH of a buffer system made by dissolving 1.2 g of acetic acid and 0.82 g ofsodium acetate in 500 ml of distilled water (pKa of acetic acid = 4.7)