The nitrogen and protein content of a 0.757 g sample of flour sample was analyzed using Kjeldahl analysis. After digestion, the liberated NH3 was distilled in a flask containing boric acid. Titration requires 12.45 mL of standard 0.100 M HCI to reach the desired endpoint. Calculate the weight percent of protein in the sample of flour considering that there is 14.76 g N per 100g protein.

The nitrogen and protein content of a 0.757 g sample of flour sample was analyzed using Kjeldahl analysis. After digestion, the liberated NH3 was distilled in a flask containing boric acid. Titration requires 12.45 mL of standard 0.100 M HCI to reach the desired endpoint. Calculate the weight percent of protein in the sample of flour considering that there is 14.76 g N per 100g protein.

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

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

See similar textbooks

Similar questions

A chemistry student needs to standardize a fresh solution of sodium hydroxide. He carefully weighs out 283. mg of oxalic acid (H,C,04), a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250. mL of distilled water. The student then titrates the oxalic acid solution with his sodium hydroxide solution. When the titration reaches the equivalence point, the student finds he has used 70.8 mL of sodium hydroxide solution. Calculate the molarity of the student's sodium hydroxide solution. Be sure your answer has the correct number of significant digits. M x10
To a 25.00 mL volumetric flask, a lab technician adds a 0.425 g sample of a weak monoprotic acid, HA, and dilutes to the mark with distilled water. The technician then titrates this weak acid solution with 0.0810 M KOH. She reaches the endpoint after adding 48.89 mL of the KOH solution. Determine the number of moles of the weak acid in the solution. moles of weak acid: mol Determine the molar mass of the weak acid. molar mass = g/mol After the technician adds 18.61 mL of the KOH solution, the pH of the mixture is 4.65. Determine the pK, of the weak acid. pKa
A chemistry student needs to standardize a fresh solution of sodium hydroxide. She carefully weighs out 316.mg of oxalic acid H2C2O4 , a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250.mL of distilled water. The student then titrates the oxalic acid solution with her sodium hydroxide solution. When the titration reaches the equivalence point, the student finds she has used 93.2mL of sodium hydroxide solution. Calculate the molarity of the student's sodium hydroxide solution. Be sure your answer has the correct number of significant digits.
0.3456 g of a solid acid is dissolved in 50 mL of water in a flask and a few drops of phenolphthalein are added to the solution. A buret containing 0.2545 M NaOH is prepared with an initial volume of 10.50 mL. The acid is accidentally titrated with the base beyond the end point, so 1.52 mL of 0.187 M HCl are added to the flask. The titration with the base is continued to a final volume reading of 40.55 mL. Calculate the molar mass of the solid acid.
An analytical chemist weighs out 0.112 g of an unknown monoprotic acid into a 250 mL volumetric flask and dilutes to the mark with distilled water. He then titrates this solution with 0.1300M NaOH solution. When the titration reaches the equivalence point, the chemist finds he has added 9.6 mL of NaOH solution. Calculate the molar mass of the unknown acid. Be sure your answer has the correct number of significant digits. mol
A solution of sodium hydroxide is standardized against potassium hydrogen phthalate (molecular mass = 204.224 g mol-1). From the following data, calculate the molarity of the NaOH solution. The mass of the KHP is 0.7840 g. Before the titration the buret reading was 0.8400 mL and afterwards it was 39.20 mL. A 85.12 mL sample of a solution of sulfuric acid, H2SO4, is neutralized by 59.82 mL of the NaOH solution from the problem above. Calculate the molarity of the sulfuric acid solution.
A chemistry student needs to standardize a fresh solution of sodium hydroxide. He carefully weighs out 626. mg of oxalic acid (H,C,04), a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250. mL of distilled water. The student then titrates the oxalic acid solution with his sodium hydroxide solution. When the titration reaches the equivalence point, the student finds he has used 145.9 mL of sodium hydroxide solution. Calculate the molarity of the student's sodium hydroxide solution. Round your answer to 3 significant digits. MAR 3. ... MacBook 44 DI DD 000 000 F10 F9 F8
In a lab, you diluted a sample of bleach to 1/10 concentration in a 250 volumetric flask. Then quantitatively transferred 25 ml of the 1/10 concentration diluted bleach into a beaker and titrated it with a standard sodium thiosulfate solution that has a molarity of 0.1215M. You repeated this 3 times. The data below is the amount of sodium thiosulfate that was titrated in the 3 runs. Calculate the molarity in each run of the diluted bleach and the concentration of undiluted bleach sample. Titration 1: 45.55 ml Titration 2: 45.67 ml Titration 6: 45.58 ml
The flask contains 10.0 mL HCl and a few drops of phenolphthalein indicator. The buret contains 0.140 M NaOH. It requires 11.0 mL of the NaOH solution to reach the end point of the titration. What is the initial concentration of HCl?
Many chemical compounds contain impurities. Crude potassium carbonate (K2CO3) obtained from the chemical supplier is assayed for purity in the following way: 8.450 g of crude potassium carbonate is weighed out into a flask and dissolved in water. The final volume was completed to 0.500 L with distilled water. 20.00 mL sample is taken from this solution and placed in a flask. Potassium carbonate is then titrated to the equivalence point with 17.80 mL of 0.2050 M HCl solution. What is the percent purity of potassium carbonate in this sample? K2CO3 + HCl  KCl + H2O + CO2
A chemistry student needs to standardize a fresh solution of sodium hydroxide. He carefully weighs out 86. mg of oxalic acid (H,C,04), a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250. mL of distilled water. The student then titrates the oxalic acid solution with his sodium hydroxide solution. When the titration reaches the equivalence point, the student finds he has used 37.0 mL of sodium hydroxide solution. Calculate the molarity of the student's sodium hydroxide solution. Be sure your answer has the correct number of significant digits. x10
A chemistry student needs to standardize a fresh solution of sodium hydroxide. He carefully weighs out 150. mg of oxalic acid (H₂C₂O4), a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250. mL of distilled water. The student then titrates the oxalic acid solution with his sodium hydroxide solution. When the titration reaches the equivalence point, the student finds he has used 77.1 mL of sodium hydroxide solution. Calculate the molarity of the student's sodium hydroxide solution. Round your answer to 3 significant digits. x10 M X 5 ?