About starting quantities Use about 0.120 g of the unknown diprotic acid dissolved in 100 mL of distilled water. Note the concentration of the standardized NaOH solution All burette readings need to be recorded to two decimal places Guiding Q: What is the identity of the unknown diprotic fraid by comparing pH & mm using a list of 5 diprotic Acids: Claim: St evidence: -506 mm:MA Malonic Acid (mA) step H: 5.06 10K 106 : 2nd pH 8.9610-896-Koz eq. H,C,H,O. Justification. Ка PH-pka' -10-pk Ko = Kaž = 7×10 mol nation of 3pts Maloric Acid : K₂ = 1.5( K=2.0(10) variation 3pts Your Task In this investigation you will monitor the pH of an unknown diprotic acid solution as it is titrated with a standardized sodium hydroxide solution. Using the pH curve, you will determine the molar mass and identity of the unknown acid From the following list of five diprotic acids. You should confirm the identity by comparing the pH at the half-equivalence points with the accepted pKa1 and pKa2 values. Diprotic Acid Oxalic Acid Formula H2C2O4 Molecular weight 90 g/mol Ka1 Ka2 6.0 x 10-2 6.1 x 10-5 Malonic Acid H2C3H2O4 104 g/mol 1.5 x 10-3 2.0 x 10-6 Maleic Acid H2C4H2O4 116 g/mol 1.2 x 10-2 5.9 x 10-7 Malic Acid H2C4H4O5 134 g/mol 3.5 x 10-4 6.3 x 10-6 Tartaric Acid H2C4H4O6 150 g/mol 1.0 x 10-3 4.6 x 10-5 Guiding Question What is the identity of an unknown diprotic acid? Supporting Calculations. Include an annotated sample calculation showing how you determined the molar mass of the unknown diprotic acid (i.e. How did you find the equivalence point, and use that value to calculate the molar mass of the unknown acid?). Include an annotated calculation showing how you determined the Ka₁ and Kaz (i.e. How did you find Ka1 and Ka2?). Provide a percent error comparing your experimental molar mass to the accepted value. File Home Insert Page Layout Formulas Data Review View Help Cut Copy Calibri 11 AA == Wrap Text General v Paste BIU A Merge & Center $% 9000 Conditional Format as Format Painter Formatting Table Clipboard 5 Font 5 Alignment Number S Styles B11 X ✓ fx 22.5 A B C D E F G H I J K L M N 1 pH 2 Moles NaOH 3 Moles Unknown Acid 4 Molarity Unknown Acid 5 Total Moles Acid 6 Molar Mass of Acid + 7 Initial NaOH (mL) 42.5 8 Initial pH 2.91 9 Volume 1st half 7.5 10 Volume 1st EP 12.5 11 Volume 2nd half 22.5 12 Volume 2nd EP 26.5 13 14 15 16 17 18 19 20 21 22 23 First Equivalence Point Time: 114 s pH: 5.06 Second Equivalence Point Time: 200 s pH: 8.96 2200.0 6370 T Time 0
About starting quantities Use about 0.120 g of the unknown diprotic acid dissolved in 100 mL of distilled water. Note the concentration of the standardized NaOH solution All burette readings need to be recorded to two decimal places Guiding Q: What is the identity of the unknown diprotic fraid by comparing pH & mm using a list of 5 diprotic Acids: Claim: St evidence: -506 mm:MA Malonic Acid (mA) step H: 5.06 10K 106 : 2nd pH 8.9610-896-Koz eq. H,C,H,O. Justification. Ка PH-pka' -10-pk Ko = Kaž = 7×10 mol nation of 3pts Maloric Acid : K₂ = 1.5( K=2.0(10) variation 3pts Your Task In this investigation you will monitor the pH of an unknown diprotic acid solution as it is titrated with a standardized sodium hydroxide solution. Using the pH curve, you will determine the molar mass and identity of the unknown acid From the following list of five diprotic acids. You should confirm the identity by comparing the pH at the half-equivalence points with the accepted pKa1 and pKa2 values. Diprotic Acid Oxalic Acid Formula H2C2O4 Molecular weight 90 g/mol Ka1 Ka2 6.0 x 10-2 6.1 x 10-5 Malonic Acid H2C3H2O4 104 g/mol 1.5 x 10-3 2.0 x 10-6 Maleic Acid H2C4H2O4 116 g/mol 1.2 x 10-2 5.9 x 10-7 Malic Acid H2C4H4O5 134 g/mol 3.5 x 10-4 6.3 x 10-6 Tartaric Acid H2C4H4O6 150 g/mol 1.0 x 10-3 4.6 x 10-5 Guiding Question What is the identity of an unknown diprotic acid? Supporting Calculations. Include an annotated sample calculation showing how you determined the molar mass of the unknown diprotic acid (i.e. How did you find the equivalence point, and use that value to calculate the molar mass of the unknown acid?). Include an annotated calculation showing how you determined the Ka₁ and Kaz (i.e. How did you find Ka1 and Ka2?). Provide a percent error comparing your experimental molar mass to the accepted value. File Home Insert Page Layout Formulas Data Review View Help Cut Copy Calibri 11 AA == Wrap Text General v Paste BIU A Merge & Center $% 9000 Conditional Format as Format Painter Formatting Table Clipboard 5 Font 5 Alignment Number S Styles B11 X ✓ fx 22.5 A B C D E F G H I J K L M N 1 pH 2 Moles NaOH 3 Moles Unknown Acid 4 Molarity Unknown Acid 5 Total Moles Acid 6 Molar Mass of Acid + 7 Initial NaOH (mL) 42.5 8 Initial pH 2.91 9 Volume 1st half 7.5 10 Volume 1st EP 12.5 11 Volume 2nd half 22.5 12 Volume 2nd EP 26.5 13 14 15 16 17 18 19 20 21 22 23 First Equivalence Point Time: 114 s pH: 5.06 Second Equivalence Point Time: 200 s pH: 8.96 2200.0 6370 T Time 0
Chemistry: Principles and Practice
3rd Edition
ISBN:9780534420123
Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer
Publisher:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer
Chapter15: Solutions Of Acids And Bases
Section: Chapter Questions
Problem 15.130QE: A solution is made by dissolving 15.0 g sodium hydroxide in approximately 450 mL water. The solution...
Related questions
Question
I need help with this question and the answer should be Malonic acid. Also please make the answer and each steps clear, since I been having issue getting a clear steps and answer. Also the all the infromation/data should be in the images to answer question.
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 2 steps
Recommended textbooks for you
Chemistry: Principles and Practice
Chemistry
ISBN:
9780534420123
Author:
Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer
Publisher:
Cengage Learning
Introductory Chemistry: A Foundation
Chemistry
ISBN:
9781337399425
Author:
Steven S. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Chemistry: Principles and Practice
Chemistry
ISBN:
9780534420123
Author:
Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer
Publisher:
Cengage Learning
Introductory Chemistry: A Foundation
Chemistry
ISBN:
9781337399425
Author:
Steven S. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry: An Atoms First Approach
Chemistry
ISBN:
9781305079243
Author:
Steven S. Zumdahl, Susan A. Zumdahl
Publisher:
Cengage Learning