Concept explainers
Interpretation:
The substances present in the solution being titrated when it has been titrated halfway to the equivalence point have to be stated. The relation of pH of the half-titrated solution to the
Concept introduction:
pH of a solution is the value of negative logarithm of the concentration of hydrogen ions in a solution. An acidic solution has a pH below
Want to see the full answer?
Check out a sample textbook solutionChapter 9 Solutions
Bundle: Chemistry for Today: General, Organic, and Biochemistry, Loose-Leaf Version, 9th + LMS Integrated OWLv2, 4 terms (24 months) Printed Access Card
- The titration of 0.100 M acetic acid with 0.100 M NaOH is described in the text. What is the pH of the solution when 35.0 mL of the base has been added to 100.0 mL of 0.100 M acetic acid?arrow_forwardYou are given the following acidbase titration data, where each point on the graph represents the pH after adding a given volume of titrant (the substance being added during the titration). a What substance is being titrated, a strong acid, strong base, weak acid, or weak base? b What is the pH at the equivalence point of the tiration? c What indicator might you use to perform this titration? Explain.arrow_forwardConsider the nanoscale-level representations for Question 110 of the titration of the aqueous weak acid HX with aqueous NaOH, the titrant. Water molecules and Na+ ions are omitted for clarity. Which diagram corresponds to the situation: After a very small volume of titrant has been added to the initial HX solution? When enough titrant has been added to take the solution just past the equivalence point? Halfway to the equivalence point? At the equivalence point? Nanoscale representations for Question 110.arrow_forward
- Many natural processes can be studied in the laboratory but only in an environment of controlled pH. Which of these combinations is the best to buffer the pH at approximately 7? Explain your choice. H3PO4/NaH2PO4 NaH2PO4/Na2HPO4 Na2HPO4/Na3PO4arrow_forwardThe weak base ethanolamine. HOCH2CH2NH2, can be titrated with HCl. HOCH2CH2NH2(aq)+H3O+(aq)HOCH2CH2NH3+(aq)+H2O(l) Assume you have 25.0 mL of a 0.010 M solution of ethanolamine and titrate it with 0.0095 M HCl. (Kb for ethanolamine is 3.2 107.) (a) What is the pH of the ethanolamine solution before the titration begins? (b) What is the pH at the equivalence point? (c) What is the pH at the halfway point of the titration? (d) Which indicator in Figure 17.11 would be the best choice to detect the equivalence point? (e) Calculate the pH of the solution after adding 5.00, 10.0, 20.0, and 30.0 mL of the acid. (f) Combine the information in parts (a), (b), (c), and (e), and plot an approximate titration curve.arrow_forwardA student was required to prepare 250.0 mL of a cyanoacetic acid/sodium cyanoacetate buffer in which the concentration of the weak acid component was 0.06 M and the concentration of the conjugate base was 0.028 M. The student was supplied with 0.512 M cyanoacetic acid and 1.0M NaOH to perform this task. What volume (in mL) of the acid would the student need to prepare this buffer solution? Hint: assume that all of the conjugate base comes directly from the reaction of NaOH with the weak acid (in other words, there is negligible dissociation of the weak acid). Please enter answers with 2 decimal places.arrow_forward
- You have a 18 mL sample of acetylcholine (a neurotransmitter) with an unknown concentration and a pH of 8.35. You incubate this sample with the enzyme acetylcholinesterase to convert all of the acetylcholine to choline and acetic acid. The acetic acid dissociates to yield acetate and hydrogen ions. At the end of the incubation period, you measure the pH again and find that it has decreased to 6.03. Assuming there was no buffer in the assay mixture, determine the number of nanomoles of acetylcholine in the original 18 mL sample.arrow_forwardYou have a 15 mL sample of acetylcholine (a neurotransmitter) with an unknown concentration and a pH of 8.06. You incubate this sample with the enzyme acetylcholinesterase to convert all of the acetylcholine to choline and acetic acid. The acetic acid dissociates to yield acetate and hydrogen ions. At the end of the incubation period, you measure the pH again and find that it has decreased to 5.91. Assuming there was no buffer in the assay mixture, determine the number of nanomoles of acetylcholine in the original 15 mL sample. O= CH3 Acetylcholine H₂O CH,—C−O−CH,—CH,—*N-CH, → HO−CH,—CH,—*N–CH, + CH,—C−O + H* CH3 CH 3 Choline CH3 Acetatearrow_forwardA chemistry graduate student is given 300.mL of a 1.10M hydrocyanic acid (HCN) solution. Hydrocyanic acid is a weak acid with =Ka×4.9*10^−10. What mass of NaCN should the student dissolve in the HCN solution to turn it into a buffer with pH =9.24? You may assume that the volume of the solution doesn't change when the NaCN is dissolved in it. Be sure your answer has a unit symbol, and round it to 2 significant digits.arrow_forward
- Define and explain the significance of the equivalence point of a titration. Identify the role of the indicator in this context.arrow_forwardDescribe the pH changes that occur during the titration of a weak base by a strong acid. What is meant by the term equivalence point?arrow_forwardAn analytical chemist is titrating 213.4 mL of a 0.3200M solution of butanoic acid (HC,H,CO,) with a 0.6400M solution of NaOH. The p K of butanoic acid is 4.82. Calculate the pH of the acid solution after the chemist has added 115.5 mL of the NaOH solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of NaOH solution added. Round your answer to 2 decimal places. pH = 0arrow_forward
- General Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage Learning
- Chemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry: Matter and ChangeChemistryISBN:9780078746376Author:Dinah Zike, Laurel Dingrando, Nicholas Hainen, Cheryl WistromPublisher:Glencoe/McGraw-Hill School Pub CoChemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage Learning