After 10.0 mL of an aqueous solution containing 1.235 mg of a drug extracted with 5.0 mL of toluene the aqueous layer was found to contain 0.346 mg of the compound. (a) Calculate the distribution coefficient for the drug between the two solvents. (b) How many 10.0-mL extractions would be required to recover 99.0% of the drug from 20.0 mL of water? What volume of toluene would be used?

After 10.0 mL of an aqueous solution containing 1.235 mg of a drug extracted with 5.0 mL of toluene the aqueous layer was found to contain 0.346 mg of the compound. (a) Calculate the distribution coefficient for the drug between the two solvents. (b) How many 10.0-mL extractions would be required to recover 99.0% of the drug from 20.0 mL of water? What volume of toluene would be used?

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter11: Properties Of Solutions

Section: Chapter Questions

Problem 117AE: Patients undergoing an upper gastrointestinal tract laboratory test are typically given an X-ray...

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(d) A sample contains a mixture of ammonium carbonate (NH4)2CO3, sodium carbonate Na2CO3, and sodium chloride NaCl. Thermogravimetric analysis indicates that a 0.0965-g portion of this sample loses 0.0574 g over a temperature range of 50-75 oC and then loses another 0.0124 g at 800 oC.(i) What causes the weight loss at 50-75 oC? (ii) What species will remain after being heated to 800 oC? (iii) What is the composition of the original sample? Given: Atomic masses: H = 1.008; C = 12.011; N = 14.007; Na = 22.99; O = 15.999;Cl = 35.45.
(c) What is the minimum distribution ratio that permits removal of 99% of a solute from 50.0 mL of water with (i) two 20.0-mL extractions with an organic solvent; (ii) four 10.0-mL extractions with the organic solvent?
A STOCK SOLUTION containing 0.1581 g/L K2CrO4 was prepared.In order to make the CALIBRATION STANDARD, 5 ml of the STOCK was transferredinto a 50ml volumetric flask and then diluted with an appropriate solvent.Calculate:(a) The ppm of K2CrO4 in the CALIBRATION STANDARD.(b) The molarity of K2CrO4 in the CALIBRATION STANDARD. (c) Calculate the molar absorptivity of K2CrO4 (at 371.0 nm). Assume that Beer's Law isobeyed over this concentration range.At 371.0 nm, this CALIBRATION STANDARD in a cell of path length 1.00 cm gave a %T of 59.752.
Oral rehydration salts are stated to contain the following components: Sodium Chloride 3.5g Potassium Chloride 1.5g Sodium Citrate 2.9g Anhydrous Glucose 20.0g 8.342 g of oral rehydration salts are dissolved in 500 ml of water. 5 ml of the solution is diluted to 100 ml and then 5 ml is taken from the diluted sample and is diluted to 100 ml. The sodium content of the sample is then determined by flame photometry. The sodium salts used to prepare the mixture were: Trisodium citrate hydrate (C6H5Na3O7, 2H2O) MW 294.1 and sodium chloride (NaCl) NW 58.5. Atomic weight of Na = 23. The content of Na in the diluted sample was determined to be 0.3210 mg/100 ml. Determine the % of stated content of Na in the sample. The stated should be 104.5, how??
Oral rehydration salts are stated to contain the following components: Sodium Chloride 3.5g Potassium Chloride 1.5g Sodium Citrate 2.9g Anhydrous Glucose 20.0g 8.342 g of oral rehydration salts are dissolved in 500 ml of water. 5 ml of the solution is diluted to 100 ml and then 5 ml is taken from the diluted sample and is diluted to 100 ml. The sodium content of the sample is then determined by flame photometry. The sodium salts used to prepare the mixture were: Trisodium citrate hydrate (C6H5Na3O7, 2H2O) MW 294.1 and sodium chloride (NaCl) NW 58.5. Atomic weight of Na = 23. The content of Na in the diluted sample was determined to be 0.3210 mg/100 ml. Determine the % of stated content of Na in the sample.
The distribution coefficient, KD (ether/water), between ether and water for aspirin at room temperature is 3.5. What weight of aspirin would be extracted by a single extraction with 60 ml of water from a solution of 10 grams of aspirin in 100 ml of ether? Calculate the weight of aspirin which would be removed by three extractions with 20 ml portions of water.
An analysis of city drinking water for total hardness was done by two students in the laboratory and produced the following results (in ppm CaCO3): Student A: 228.3, 226.4, 226.9, 227.1, and 228.6. Student B: 229.5, 226.1, 230.7, 223.8, and 227.5 what is the coefficient variation?
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Suppose you are interested to extract most of the 5 grams of vitamin C dissolved in 100 mL of water using dichloromethane. The distribution coefficient for vitamin C between dichloromethane and water is 10. (KD vitamin C (CH2Cl2/H2O) = 10) (a) How much of vitamin C will be extracted in the CH2Cl2 if you extract it from water one time with 75 mL of CH2Cl2? (b)How much of vitamin C will be extracted in the CH2Cl2 if you extract it from water three times with 25 mL of CH2Cl2? (Show computation)
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6) 100.01 mg Cu(NO3)2 is diluted to 100.00 mL with distilled water. Calculate the ppm of the resulting solution and also calculate the uncertainty of the result. Report the result with the suitable number of significant figures (the uncertainty of 100.00 mL capacity volumetric flask is 0.07 mL, the uncertainty coming from the weighing is 0.05 mg).
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