Four tablet samples (1.6308 g) which contain acetylsalicylic acid were dissolved in a 100 mL water/ethanol mixture. A 25-mL aliquot was obtained and titrated with standard 0.1273 N NaOH solution using a pH meter. The potentiometric data are given below. Calculate the % acetylsalicylic acid (EW=180.157 g/mol) per tablet. Prove that the active ingredient is indeed acetylsalicylic acid (pKa=3.48).

Four tablet samples (1.6308 g) which contain acetylsalicylic acid were dissolved in a 100 mL water/ethanol mixture. A 25-mL aliquot was obtained and titrated with standard 0.1273 N NaOH solution using a pH meter. The potentiometric data are given below. Calculate the % acetylsalicylic acid (EW=180.157 g/mol) per tablet. Prove that the active ingredient is indeed acetylsalicylic acid (pKa=3.48).

Chemistry: An Atoms First Approach

2nd Edition

ISBN:9781305079243

Author:Steven S. Zumdahl, Susan A. Zumdahl

Publisher:Steven S. Zumdahl, Susan A. Zumdahl

Chapter14: Acid- Base Equilibria

Section: Chapter Questions

Problem 118CP: Malonic acid (HO2CCH2CO2H) is a diprotic acid. In the titration of malonic acid w ith NaOH,...

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Malonic acid (HO2CCH2CO2H) is a diprotic acid. In the titration of malonic acid w ith NaOH, stoichiometric points occur at pH = 3.9 and 8.8. A 25.00-mL sample of malonic acid of unknown concentration is titrated with 0.0984 M NaOH, requiring 31.50 mL of the NaOH solution to reach the phenolphthalein end point. Calculate the concentration of the initial malonic acid solution. (Sec Exercise 113.)
Students Mola and Rity were tasked to analyze the acidity of a 10.0-mL fermented milk sample diluted with water in a 250-mL volumetric flask. Mola obtained a 15.0-mL aliquot of this solution, diluted it to 50.0 mL, and then titrated this diluted sample. Titration data were given to Rity and she found out that the 50.0-mL diluted sample contains 0.21 mmol of lactic acid. MW: Lactic Acid (90.08) a. What is the lactic acid concentration (in M) of the titrated sample? b. Determine the lactic acid content (in M) of the 10.0-mL fermented milk sample. c. What is the lactic acid concentration (in %w/v) of the 10.0-mL fermented milk sample?
A cleaning product has 10.0 % oxalic acid (H2C2O4, pka1=1.42, pka2=4.4) as one of the ingredients. How many mL of the sample will you use to do titration with 0.50 M NaOH, such that volume of titrant will be 50.0 mL at the phenolphthalein endpoint?Please show complete step-by-step solution.
For Ca2+ and Mg2+ determinations in a tap water sample, two 50 mL aliquots were pipetted and placed in different Erlenmeyer flasks. The first of them had the pH adjusted to 12 (Ca2+ titration) and the second to 10 (Ca2+ +Mg2+ titration). The volumes of EDTA (5.07*10-3 mol/L) used in the first and second titrations were 2.40 and 4.80 mL, respectively. Calculate: a) The concentration of Ca2+ in mg/L in the water sampleb) The concentration of Mg2+ in mg/L in the water sample
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Calculate the pH of two HCl solution based on their concentrations of 0.001 and0.0001 M. Then calculate the pH of a solution when you add each of these to a closed carbonicacid system with mcarb-t = mH2CO3 + mHCO3- + mCO32- = 0.01 m and pH = 6. At that pH, mH2CO3 =10-2.16; mHCO3- =10-2.51; mCO32- is negligible.
A sample of 50.00 mL of 0.1000 M aqueous solution of chloroacetic acid, CH2ClCOOH (K1= 1.4 × 10-3), is titrated with a 0.1000 M NaOH solution. Calculate the pH at the following stages in the titration, and plot thetitration curve: 0, 5.00, 25.00, 49.00, 49.90, 50.00, 50.10, and 55.00 mL NaOH.
A 50.00-mL sample of a 1.00 M solution of the diprotic acid H2A (Ka1 = 1.0 × 10–6 and Ka2 = 1.0 × 10–10) is titrated with 2.00 M NaOH. How many mL of 2.00 M NaOH must be added to reach a pH of 12? Give answer in 15 min.
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A different titration experiment using a 0.127M standardized NaOH solution to titrate a 27.67 mL solution with an unknown Molarity concentration (M) of sulfuric acid (H2SO4) gave the following molarities for 3 trials. Initial Burette Reading (mL) Final Burette Reading (mL) Delivered vol (mL) Acid Concentration (M) Trial 1 0.0358 Trial 2 0.0341 Trial 3 0.0331 From the 3 trials, determine the average Molarity concentration of the H2SO4 to 3 significant digits. Don't include a unit. From the 3 trials, determine the standard deviation of the Molarity concentration of the H2SO4 to 3 significant digits. Don't include a unit.From the 3 trials, determine the relative standard deviation of the Molarity concentration of the H2SO4 to 3 significant digits. Don't include a unit. Do you think the above experiment was accurate? Precise? Explain your answer using supporting values.