Strong Bases/Acids vs. Weak Bases/Acids The 4 Titration Curves Combinations NaOH + HCI Strong Base Strong Acid Strong Base+ Weak Acid HOOD HO+ HOEN Weak Base Strong Acid IOH + HO'HN NH.OH + CH.COOH Weak Base Weak Acid 4. Explain why the titrations which began with CH3COOH started from a higher pH value compared to those which began with HCI. 5. What was the purpose of adding the indicator to each titration? 6. Two titrations ended with the pH well above 10 the other two titrations ended with the pH below 10. Explain why this occurred.

Strong Bases/Acids vs. Weak Bases/Acids The 4 Titration Curves Combinations NaOH + HCI Strong Base Strong Acid Strong Base+ Weak Acid HOOD HO+ HOEN Weak Base Strong Acid IOH + HO'HN NH.OH + CH.COOH Weak Base Weak Acid 4. Explain why the titrations which began with CH3COOH started from a higher pH value compared to those which began with HCI. 5. What was the purpose of adding the indicator to each titration? 6. Two titrations ended with the pH well above 10 the other two titrations ended with the pH below 10. Explain why this occurred.

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

Chapter16: Reactions Between Acids And Bases

Section: Chapter Questions

Problem 16.93QE

See similar textbooks

Similar questions

When 40.00 mL of a weak monoprotic acid solution is titrated with 0.100-M NaOH, the equivalence point is reached when 35.00 mL base has been added. After 20.00 mL NaOH solution has been added, the titration mixture has a pH of 5.75. Calculate the ionization constant of the acid.
Consider the following pH curves for 100.0 mL of two different acids with the same initial concentration each titrated by 0.10 M NaOH. a. Which plot represents a pH curve of a weak acid, and which plot is for a strong acid? How can you tell? Cite three differences between the plots that help you decide. b. In both cases the pH is relatively constant before the pH changes greatly. Does this mean that at some point in each titration each solution was a buffered solution? c. True or false? The equivalence point volume for each titration is the same. Explain your answer. d. True or false? The pH at the equivalence point for each titration is the same. Explain your answer.
Sketch the titration curve for a weak base titrated by a strong acid. Weak basestrong acid titration problems also follow a two-step procedure. What reaction takes place in the stoichiometry part of the problem? What is assumed about this reaction? At the various points in your titration curve, list the major species present after the strong acid (HNO3, for example) reacts to completion with the weak base, B. What equilibrium problem would you solve at the various points in your titration curve to calculate the pH? Why is pH 7.0 at the equivalence point of a weak basestrong acid titration? If pH = 6.0 at the halfway point to equivalence, what is the Kb value for the weak base titrated? Compare and contrast the titration curves for a strong basestrong acid titration and a weak basestrong acid titration.
Draw the general titration curve for a strong acid titrated by a strong base. At the various points in the titration, list the major species present before any reaction takes place and the major species present after any reaction takes place. What reaction takes place in a strong acidstrong base titration? How do you calculate the pH at the various points along the curve? What is the pH at the equivalence point for a strong acidstrong base titration? Why?
Sketch a pH curve for the titration of a weak acid (HA) with a strong base (NaOH). List the major species, and explain how you would go about calculating the pH of the solution at various points, including the halfway point and the equivalence point.
For the titration of 50.0 mL of 0.150 M ethylamine. C2H5NH2, with 0.100 M HCl, find the pH at each of the following points, and then use that information to sketch the titration curve and decide on an appropriate indicator. (a) At the beginning, before HCl is added (b) At the halfway point in the titration (c) When 75% of the required acid has been added (d) At the equivalence point (e) When 10.0 mL more HCl has been added than is required (f) Sketch the titration curve. (g) Suggest an appropriate indicator for this titration.
Which of the indicators in Fig. 14-8 could be used for the titrations in Exercises 61 and 63?
You titrate 25.0 mL of 0.10 M NH3 with 0.10 M HCl. (a) What is the pH of the NH3 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) What indicator in Figure 17.11 could be used to detect the equivalence point? (e) Calculate the pH of the solution after adding 5.00, 15.0, 20.0, 22.0, and 30.0 mL of the acid. Combine this information with that in parts (a)(c) and plot the titration curve.
When a diprotic acid. H2A. is titrated with NaOH, the protons on the diprotic acid are generally removed one at a time, resulting in a pH curve that has the following generic shape: a. Notice that the plot has essentially two titration curves. If the first equivalence point occurs at 100.0 mL NaOH added, what volume of NaOH added corresponds to the second equivalence point? b. For the following volumes of NaOH added, list the major species present after the OH reacts completely. i. 0 mL NaOH added ii. between 0 and 100.0 mL NaOH added iii. 100.0 mL NaOH added iv. between 100.0 and 200.0 mL NaOH added v. 200.0 mL NaOH added vi. after 200.0 mL NaOH added c. If die pH at 50.0 mL NaOH added is 4.0 and the pH at 150.0 mL NaOH added is 8.0, determine the values Ka and Ka. for the diprotic acid. d.
Consider the titration of 100.0 mL of 0.200 M HONH2 by 0.100 M HCI. (Kb for HONH2 = 1.1 108.) a. Calculate the pH after 0.0 mL of HCl has been added. b. Calculate the pH after 25.0 mL of HCl has been added. c. Calculate the pH after 70.0 mL of HCl has been added. d. Calculate the pH at the equivalence point. e. Calculate the pH after 300.0 mL of HCl has been added. f. At what volume of HCl added does the pH = 6.04?
2. If an acetic acid/sodium acetate buffer solution is prepared from 100. mL of 0.10 M acetic acid what volume of 0.10 M sodium acetate must be added to have a pH of 4.00? 100. mL 50. mL 36 mL 18 mL
Determine the dominant acid-base equilibrium that results when each of the following pairs of solutions is mixed. Indicate the equilibrium by writing 1 for a strong acid, 3 for a weak acid, 4 for an acidic buffer, 7 for a neutral solution, 10 for a basic buffer, 11 for a weak base, and 13 for a strong base. (a) 10.0 mL of 0.15 M NaOH + 15.0 mL of 0.10 M HNO3 (b) 25.0 mL of 0.10 M HCl + 10.0 mL of 0.25 M NH3 (c) 50.0 mL of 0.050 M NaOH + 50.0 mL of 0.10 M NH3 (d) 50.0 mL of 0.10 M NH3 + 50.0 mL of 0.05 M HCl