An analytical chemist weighs out 0.120 g of an unknown diprotic acid into a 250 mL volumetric flask and dilutes to the mark with distilled water. She then titrates this solution with 0.0500 M NaOH solution. When the titration reaches the equivalence point, the chemist finds she has added 35.8 mL of NaOH solution. Calculate the molar mass of the unknown acid. Be sure your answer has the correct number of significant digits. mol

An analytical chemist weighs out 0.120 g of an unknown diprotic acid into a 250 mL volumetric flask and dilutes to the mark with distilled water. She then titrates this solution with 0.0500 M NaOH solution. When the titration reaches the equivalence point, the chemist finds she has added 35.8 mL of NaOH solution. Calculate the molar mass of the unknown acid. Be sure your answer has the correct number of significant digits. mol

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.)
A 0.210-g sample of an acid (molar mass = 192 g/mol) is titrated with 30.5 mL of 0.108 M NaOH to a phenolphthalein end point. Is the acid monoprotic, diprotic, or triprotic?
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.
Give typed solution A student analyzed a CaCO3 antacid tablet by neutralizing the base with an excess of .60 M HCL and back-titrating the excess with .50M NaOH. He recorded the following data: mass of tablet = 1.3g amount of active ingredient CaCO3 per label = 500 mg volume of HCl added: 25 mL initial buret reading : 34 mL final buret reading : 47.4 mL If the concentration of the provided HCl is actually higher than .60M, would the determined mass of CaCO3 in the antacid tablet be too high or too low?
H2Z is a diprotic acid with Ka1 = 3.0 × 10^-3 and Ka2 = 8.0 x 10^-8. Suppose you start with 1.00 L of 1.00 M H2Z(aq) and add 1.00 M KOH (aq) gradually. Calculate the pH at the following volumes of added strong base: a) 0.00 L; b) 0.50 L; c) 1.00 L; d) 1.50 L; e) 2.00 L. Report the pH values with 2 decimal places after dot. Write relevant chemical equations and show work on every part of this problem. f. Sketch the titration curve g. How many liters of 1.00 M KOH(ag) should be added to 1.00 L of 1.00 M H2Z to obtain a buffered solution with pH = 7.50? Hint to part g: you may calculate the moles of two salts in the buffer, then moles of K* ions in the salt, and finally consider that all K* ions come from KOH(ag).
Please answer with complete solutions. Do not use spreadsheet. Thank you A series of solutions containing NaOH, Na2CO3, and NaHCO3, alone or in compatible combination, was titrated with 0.1202 M HCl. Tabulated below are the volumes of acid needed to titrate 25.00-mL portions of each solution to (1) a phenolphthalein and (2) a bromocresol green end point. Use this information to deduce the composition of the solutions. In addition, calculate them molar concentration. (1) Phenolphthalein End Point (2) Bromocresol Green End Point a 22.42 22.44 b 15.67 42.13 c 29.64 36.42 d 16.12 32.23 e 0.00 33.33
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.
Acid-base Titration Assignment solves questions in end. if necessary use notebook to make the curve.A student conducted the following experiment in the lab. 50.00 mL of acetic acid (of unknown concentration) was pipetted into a 150 mL Erlenmeyer flask. An indicator was added and the pH of the solution was recorded. 0.1 M NaOH (a strong base) was added to the Erlenmeyer flask from a buret. The contents of the flask were continuously stirred and the pH was recorded every 2 mL using a pH meter.Data Collected: Volume of NaOH added (mL) pH 0.0 2.87 10.0 4.14 25.0 4.74 40.0 5.35 50.0 8.72 60.0 11.96 75.0 12.30 1. The chemicals involved in the titration are NaOH (a strong electrolyte) and CH3COOH (aweak electrolyte). Predict the shape of the titration curve that would be obtained from thedata above. Also predict what the pH at the equivalence point will be.2. What is the volume of NaOH at the equivalence point?3. What is the pH at the equivalence point?4. What does the…
Piperazine, C4H10N2, is a diprotic weak base (pKb1 = 4.22 and pKb2 = 8.67). A sample of piperazine is dissolved in 100.0 mL of water and titrated with 0.500 M HCl. It takes 48.00 mL of HCl to reach the second equivalence point. Calculate the pH after the following amounts of HCl have been added: 0 mL, 12.00mL, 24.00mL,36.00mL, 48.00mL, and 60.00mL
Click in the Stockroom. The stock solutions of NaCN and Na3PO4 are already approximately 0.1 M. Double-click each bottle to move them to the counter and return to the laboratory. With these solutions you can pour a small amount into a beaker that you have placed on the stir plate and place the pH probe in the solution. Record each pH in the data table. Drag each beaker to the red disposal bucket when you have finished. Were your predictions correct? If not, re-write the balanced net ionic equation below and explain the behavior of the salt in water. Data Table solution pH acidic, basic or neutral NH4Cl NaHCO3 KNO3 NaCN Na3PO4
Consider a solution initially containing 0.30 M of CH3NH2 mixed with 0.50 M of CH3NH3Cl in water. What is the pH after the addition of 6.415 mL of 0.10 M NaOH to 19.41 mL of this solution? (Kb for CH3NH2 = 4.47 × 10–4) Express your answer using at least three significant figures. Do not use scientific notation.