Study Guide for Chemistry: The Central Science
13th Edition
ISBN: 9780321949288
Author: Theodore E. Brown, James C. Hill
Publisher: PEARSON
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Textbook Question
Chapter 3, Problem 13E
You are asked to prepare an pH = 4.00 buffer starting from 1.50 L of 0.0200 M solution of benzoic acid (C6H5COOH) and any amount you need of sodium benzoate(C6H5COONa).
a. What is the pH of the benzoic acid solution prior to adding sodium benzoate?
b. How many grams of sodium benzoate should be added to prepare the buffer? Neglect the small volume change that occurs when the sodium benzoate is added.
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Students have asked these similar questions
5. A buffer is made by mixing 1.250 mol formic acid, HCOOH, with 0.750 mol sodium
formate, HCOONa in enough water for a total volume of 1.00L. The Ka of formic acid is
1.87 x 10-4
a. What is the pH of this buffer?
b. If 0.075 mol HCI is added to this buffer, what is the pH of the resulting buffer?
(assume no volume changes)
c. If 0.055 mol NaOH is added to this buffer, what is the pH of the resulting buffer?
(Assume no volume changes)
4. Use a 100-mL beaker to make 50 ml of sodium phosphate solution by mixing 0.8 ml of 2 M
monobasic NaH;PO4, 4.2 ml of 2 M dibasic N2>HPO4, and 45 ml of H20 as shown in the table.
Measure and record the pH. Pipette 20mL of this buffer solution and place it in a new 50-ml
beaker. Add 1 ml of 1 M HCI or 1 M NaOH to each separate beaker and mix well. Measure and
record the pH.
Table 4:
Buffered solution (phosphate)
Calculated pH
Measured
pH
0.8 mL of 2 M monobasic NaH,PO4 + 4.2 mL
7.66
of 2 M dibasic Na>HPO4 + 45 mL H20
25 ml above mix buffer +1 ml 1.0 M HCI
7.08
25 ml above mix buffer +1 mL 1.0 M NaOH
7.71
* The pKaz and pkaz of phosphate groups are 6.8 and 12.3, respectively.
This question is about a buffer solution made by mixing
together solutions containing ethanoic acid and sodium
ethanoate.
H3C
HO,
H3C
O`Na*
H3C
O Nat
HO
a) If you add a small amount of an acid such as dilute
hydrochloric acid to this, the pH doesn't change much. Explain
what happens to the extra hydrogen ions you have added.
b) If you add a small amount of an alkali such as sodium
hydroxide solution to the buffer solution, again the pH doesn't
change much. There are two ways in which the extra hydroxide
ions can be removed. What are they?
10:2
11/28
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Chapter 3 Solutions
Study Guide for Chemistry: The Central Science
Ch. 3.1 - You add 10.0 grams of solid copper(II) phosphate,...Ch. 3.1 - Prob. 3.1.2PECh. 3.1 - Consider a saturated solution of the salt MA3, in...Ch. 3.1 - Prob. 3.2.2PECh. 3.2 - Prob. 3.3.1PECh. 3.2 - Prob. 3.3.2PECh. 3.2 - Prob. 3.4.1PECh. 3.2 - Prob. 3.4.2PECh. 3.3 - An insoluble salt MA has a Kap of 1.0 × 10-10. Two...Ch. 3.3 - Does a precipitate form when 0.050 L of 2.0 × 10-2...
Ch. 3.3 - Under what conditions does an ionic compound...Ch. 3.3 - Prob. 3.6.2PECh. 3.4 - Prob. 3.7.1PECh. 3.4 - The following boxes represent aqueos solutions...Ch. 3.4 - Prob. 3.8.1PECh. 3.4 - Prob. 3.8.2PECh. 3.4 - Prob. 3.9.1PECh. 3.4 - Prob. 3.9.2PECh. 3.4 - For the generic equilibrium HA(aq)H+(aq)+A(aq) ,...Ch. 3.4 - Practice Exercise 2 Calculate the pH of a solution...Ch. 3.4 - Calculate the concentration of the lactate ion in...Ch. 3.4 - Practice Exercise 2 Calculate the format ion...Ch. 3.4 - Practice Exercise 1 If the pH of a buffer solution...Ch. 3.4 - Prob. 3.12.2PECh. 3.5 - Prob. 3.13.1PECh. 3.5 - Prob. 3.13.2PECh. 3.5 - Calculate the number of grams of ammonium chloride...Ch. 3.5 - Prob. 3.14.2PECh. 3.5 - Prob. 3.15.1PECh. 3.5 - Determine The pH of the original buffer described...Ch. 3.6 - An acid-base titration is performed: 250.0 mL of...Ch. 3.6 - Prob. 3.16.2PECh. 3.6 - Prob. 3.17.1PECh. 3.6 - Calculate the pH in the solution formed by adding...Ch. 3.7 - Prob. 3.18.1PECh. 3.7 - Prob. 3.18.2PECh. 3.7 - Prob. 3.19.1PECh. 3.7 - Prob. 3.19.2PECh. 3.7 - Prob. 3.20.1PECh. 3.7 - Prob. 3.20.2PECh. 3 - The accompanying graph shows the titration curves...Ch. 3 - Prob. 2ECh. 3 - Prob. 3ECh. 3 - Prob. 4ECh. 3 - Prob. 5ECh. 3 - Prob. 6ECh. 3 - Prob. 7ECh. 3 - Prob. 8ECh. 3 - Prob. 9ECh. 3 - Use information from Appendix D to calculate the...Ch. 3 - A buffer is prepared by adding 10.0 g of ammonium...Ch. 3 - You are asked to prepare a pH = 3.00 buffer...Ch. 3 - You are asked to prepare an pH = 4.00 buffer...Ch. 3 - Prob. 14ECh. 3 - Prob. 15ECh. 3 - Prob. 16ECh. 3 - Prob. 17ECh. 3 - Prob. 18ECh. 3 - Prob. 19ECh. 3 - Prob. 20ECh. 3 - 17.35 The samples of nitric and acetic acids shows...Ch. 3 - 17.36 Determine whether each of the following...Ch. 3 - Prob. 23ECh. 3 - Prob. 24ECh. 3 - Prob. 25ECh. 3 - Assume that 30.0 mL of a M solution of a week base...Ch. 3 - Prob. 27ECh. 3 - Prob. 28ECh. 3 - Prob. 29ECh. 3 - Prob. 30ECh. 3 - Consider the titration of 30.0 mL of 0.050 M NH3...Ch. 3 - Prob. 32ECh. 3 - Prob. 33ECh. 3 - Prob. 34ECh. 3 - The solubility of two slighty soluble salts of...Ch. 3 - Prob. 36ECh. 3 - 17.52
a. true or false: solubility and...Ch. 3 - If the molar solubility CaF2 at 35 C is 1.24 *10-3...Ch. 3 - Prob. 39ECh. 3 - Prob. 40ECh. 3 - using calculate the molar solubility of AgBr in a....Ch. 3 - calculate the solubility of LaF3 in grams per...Ch. 3 - Prob. 43ECh. 3 - Consider a beaker containing a saturated solution...Ch. 3 - Calculate the solubility of Mn (OH) 2 in grams per...Ch. 3 - Calculate the molar solubility of Ni (OH) 2 when...Ch. 3 - 17.63 Which of the following salts will be...Ch. 3 - For each of the following slightly soluble salts,...Ch. 3 - Prob. 49ECh. 3 - Use values of Kap for Agl and Kf for Ag (CN) 2- to...Ch. 3 - Prob. 51ECh. 3 - Prob. 52ECh. 3 - Prob. 53ECh. 3 - Calculate the minimum pH needed to precipitate Mn...Ch. 3 - Prob. 55ECh. 3 - Prob. 56ECh. 3 - Prob. 57ECh. 3 - Prob. 58ECh. 3 - Prob. 59ECh. 3 - An unknown solid is entirely soluble in water. On...Ch. 3 - Prob. 61ECh. 3 - Prob. 62ECh. 3 - 17.81
Precipitation of the group 4 cautions of...Ch. 3 - Prob. 64ECh. 3 - Prob. 65ECh. 3 - Prob. 66ECh. 3 - Furoic acid (HC5H3O3) has a K value of 6.76 x 10-4...Ch. 3 - Prob. 68ECh. 3 - Equal quantities of 0.010 M solution of an acid HA...Ch. 3 - 17.89 A biochemist needs 750 ml of an acetic...Ch. 3 - (a) Define the terms limiting reactant and excess...Ch. 3 - Prob. 72ECh. 3 - Prob. 73ECh. 3 - Prob. 74ECh. 3 - What is the pH of a solution made by mixing 0.30...Ch. 3 - Suppose you want to do a physiological experiment...Ch. 3 - Prob. 77ECh. 3 - Prob. 78ECh. 3 - For each pair of compounds, use Kap values to...Ch. 3 - Tooth enamel is composed of hydroxyapatite, whose...Ch. 3 - Salts containing the phosphate ion are added to...Ch. 3 - Prob. 82ECh. 3 - 17.103 The solubility –product constant for barium...Ch. 3 - Prob. 84ECh. 3 - Prob. 85ECh. 3 - A buffer of what pH is needed to give a Mg2+...Ch. 3 - The value of Kap for Mg3(AsO4)2 is 2.1 10-20 ....Ch. 3 - Prob. 88AECh. 3 - Prob. 89AECh. 3 - Prob. 90AECh. 3 - Prob. 91AECh. 3 - Prob. 92AECh. 3 - Prob. 93AECh. 3 - Prob. 94AECh. 3 - Prob. 95AECh. 3 - A concentration of 10-100 parts per billion (by...Ch. 3 - Prob. 97AECh. 3 - Prob. 98AECh. 3 - In nonaqueous solvents, it is possible to react HF...Ch. 3 - Prob. 100AECh. 3 - Prob. 101AECh. 3 - Prob. 102AECh. 3 - 17.9 The following graphs represent the behavior...Ch. 3 - Prob. 104AECh. 3 - 17.11 The graph below shows the solubility of a...Ch. 3 - Prob. 106IECh. 3 - Prob. 107IECh. 3 - (a) If an automobile travels 225 mi with a gas...Ch. 3 - Prob. 109IECh. 3 - Prob. 110IECh. 3 - Hydrogen cyanide, HCN, is a poisonous gas. The...Ch. 3 - Prob. 112IE
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