1-11 Exactly 5.00-mL aliquots of a solution containing phenobarbital were measured into 50.00-mL volumetric flasks and made basic with KOH. The following volumes of a standard solution of phenobarbital containing 2.000 ug/mL of phenobarbital were then introduced into each flask and the mixture was diluted to volume: 0.000, 0.500, 1.00, 1.50, and 2.00 mL. The fluorescence of each of these solutions was measured with a fluorometer, which gave values of 3.26, 4.80, 6.41, 8.02, and 9.56, respectively. (a) Plot the data. *(b) Using the plot from (a), calculate the concentration of phenobarbital in the unknown.

1-11 Exactly 5.00-mL aliquots of a solution containing phenobarbital were measured into 50.00-mL volumetric flasks and made basic with KOH. The following volumes of a standard solution of phenobarbital containing 2.000 ug/mL of phenobarbital were then introduced into each flask and the mixture was diluted to volume: 0.000, 0.500, 1.00, 1.50, and 2.00 mL. The fluorescence of each of these solutions was measured with a fluorometer, which gave values of 3.26, 4.80, 6.41, 8.02, and 9.56, respectively. (a) Plot the data. *(b) Using the plot from (a), calculate the concentration of phenobarbital in the unknown.

Introduction to General, Organic and Biochemistry

11th Edition

ISBN:9781285869759

Author:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres

Publisher:Frederick A. Bettelheim, William H. Brown, Mary K. Campbell, Shawn O. Farrell, Omar Torres

Chapter6: Solutions And Colloids

Section: Chapter Questions

Problem 6.40P: 6-40 What is the molarity of each solution? (a) 47 g of KCI dissolved in enough water to give 375 mL...

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6-40 What is the molarity of each solution? (a) 47 g of KCI dissolved in enough water to give 375 mL of solution (b) 82.6 g of sucrose, C12H22O11, dissolved in enough water to give 725 mL of solution (c) 9.3 g of ammonium sulfate, (NH4)2SO4 dissolved in enough water to give 2.35 L of solution
Exactly 10.00-mL aliquots of a solution containing phenobarbital were measured into 50.00-mL volumetric flasks and made basic with KOH. The following volumes of a standard solution of phenobarbital containing 2.000μg/mL of phenobarbital were then introduced into each flask and the mixture was diluted to volume: 0.000, 0.500, 1.00, 1.50, 2.00 mL. The fluorescence of each of these solutions was measured with a fluorimeter, which gave values of 3.26, 4.80, 6.41, 8.02, 9.56, respectively. a. plot the data. b. derive a least squares equation for the data plotted in (a). c. find the concentration of phenobarbital from the equation in (b). d. calculate a standard deviation for the concentration obtained in (c).
A solution of HCl was titrated against sodium carbonate. What is the normality of acid for Trial 3 in the given data? T1 T2 0.3562 0.3479 0.3042 Weight (g) Initial V (mL) 0.80 1.60 0.40 Final V (mL) 35.20 36.70 39.80 Vol HCI used (ml) 35.10 39.40 N of HC (eq/L) 0.1954 0.1870 Average N of HCl (eq/L)
A 30 mL sample of vinegar is titrated with 39 mL of 0.5 N Sodium Hydroxide. What is the normality of the acetic acid (CH3COOH) in vinegar? Atomic Weights :Sodium - 22.99Oxygen - 15.999Hydrogen - 1.008 Enter numerical value only; round off to 4 decimal places if necessary
You measure 15.0 mL of the H2C2O4 solution with a 100-mL graduated cylinder and add it to a 125-mL Erlenmeyer flask. Then you add two drops of the indicator, phenolphthalein, to the oxalic acid solution in the flask. You dispense the NaOH solution from the buret into the flask (while swirling the flask) until you reach the endpoint. At the endpoint, the solution in the flask turns light pink. You repeat the titration two additional times for a total of three trials. H2C2O4 (aq) + 2 NaOH (aq) --> Na2C2O4 (aq) + 2 H2O (l) (I) (II) (III) Volume of H2C2O4 used 15.00 mL 15.00 mL 15.00 mL how many Moles H2C2O4 are used in each trial?
4:11 ul LTE 4 PrepSoln-Data 1 of 2 Data sheet Preparation of Solutions Part A: Weight by volume: Prepare a 3% solution with total volume as requested. Concentration of solution 3% Volume of solution 250 ml Mass of salt required Comments: Part B: Volume by volume: Prepare a 5% ethanol solution with a total volume of 250 ml. Concentration of solution 5% Volume of solution 250 ml Volume of ethanol Comments: Part C: Preparing a solution from solid by knowing the molarity: Salt used CuSO, - KCI – NH,CI CuSO.5H20- CaClz Molecular weight Concentration of solution 0.3 M
1-3: A stock solution of 70% v/v ethanol was diluted with distilled water to prepare 1L of 21% v/v ethanol. (Density of ethanol = 0.789 g/mL; MW of ethanol = 46 g/mol) Determine the initial volume of 70% v/v ethanol used in the preparation. How much water was added to the stock solution to make 1L of the final concentration? The molarity of 5.0 mL of 70% v/v ethanol was found to be __________.
A stock solution whose concentration is 25.00 mg/mL was provided. A primary standard solution was then prepared by transferring 5.00 mL of the stock solution into a 50.00 mL volumetric flask. The primary standard solution was used to prepare three standard solutions of different concentrations by taking different volumes of aliquots into three 25.00 mL volumetric flasks: Standard Solution #1 #2 #3 Amount of Primary Solution (mL) 5.00 10.00 15.00 Three 25.00 mL volumetric flasks were then diluted to mark with water. Questions #1 What is the concentration of the primary standard solutions, expressed in units of mg/ml? #2 Re-write the concentration of the primary standard solutions obtained from Q#1 in units of μg/mL. #3 Determine the concentrations of three standard solutions in units of µg/mL. #4 What is a requirement for a "blank" solution used in calibration in spectrophotometry? Page 5 (Experiment #3)
Details Preparation of Dilute Table Solution Molarity of I₂ Standard Solution Molar Mass (g/mole) Ascorbic Acid Number of Tablets per Analysis Mass (g) Container plus 1 Tablet Mass (g) Container less 1 Tablet Mass (g) of 1 Tablet Volume (mL) of Dilute Tablet Solution Titrimetric Analysis of Dilute Tablet Solution Volume (mL) of Aliquot Portion of Dilute Tablet Solution Titrated Final Buret Reading (mL) Initial Buret Reading (mL) Volume (mL) I₂ Solution Delivered No. of mmol 1₂ Reacted No. of mmol Ascorbic Acid in Aliquot Total No. of mmol Ascorbic Acid Present in the Volumetric Flask Total Mass (mg) of Ascorbic Acid Present in 1 Tablet Average Mass Ascorbic Acid/Tablet Deviation Standard Deviation Coefficient of Variation (%RSD) Reported Composition of Tablet Trial 1 50.00 11.64 0.20 0.02512 M 176.14 1 12.2546 11.7824 0.4722 250.00 Trial 2 50.00 22.80 11.64 Trial 3 250 mg Ascorbic Acid/Tablet 50.00 11.20 0.00 mg Ascorbic Acid/Tablet
When drinking water is disinfected with chlorine, an undesired byproduct, chloroform (CHCl3), may form. Suppose a 70-kg person drinks 2 L of water every day for 70 years with a chloroform concentration of 0.08 mg/L (the drinking water standard). Potency factor for chloroform = 6.1 x 10-3 (mg/kg-day)-1 The upper-bound cancer risk for this individual. a. 0.545 b. 5.45x10-6 c. 5.45x10-4 d. 5.45x10-10 e. 14x10-6 If a city with 300,000 people in it also drinks the same amount water described in the above question, how many extra cancers per year would be expected? Assume the standard 70-year lifetime. a. 0.163 b. 1.63x10-4 c. 1.63x10-3 d. 1.63x10-6 e. 6x10-2
You want to make a solution of the primary standard sodium oxalate. It has a molecular mass of 133.999 g/mol (no error). Your analytical balance has an error of 0.2 mg. You add some weighing paper to the balance and it reads a mass of 0.23626 g. You then add sodium oxalate onto the weighing paper until the mass registers as 2.8539 g. You carefully transfer this to a 250.0 ml volumetric flask with an error of 0.1 ml and dissolve the sodium oxalate in a sufficient volume of water. What is the concentration of the oxalic acid (in M) and what is the absolute error (also in M).
Complete the table by entering the molarity of B2- for each standard solution. Show an illustrative calculation for tube ‘A’. Use the dilution formula and express each result to one more digit than allowed by applying the rules of significant figures. Standard Volume of stock B2- solution taken, mL Molarity of dilute B2 Construct a graph of Absorbance vs. molarity of B2- in Excel using the data in the preceding table. Make certain to title the graph and include axes labels with proper units. Absorbance is dimensionless (has no unit). Add a linear trendline to the graph but do not set the y-intercept to zero Solid M2B is added to 25 mL of water, the resulting mixture is continually stirred for 1 hour. At this point, it is assumed that equilibrium (eqn 3) has been established. The mixture is transferred to a test tube, and the test tube is centrifuged to assure that any residual solid M2B is fully settled out. A portion of the supernatant in the test tube is carefully…