Explanation a) 2 M acetic acid and 2 M sodium acetate. Consider the degree of dissociation to be x . The ionization reaction and the ICE table is represented below. CH 3 COOH ( aq ) ⇌ H + ( aq ) + CH 3 COO − ( aq ) Initial ( M ) 2 0 2 Change ( M ) 2 − x + x 2 + x Equilibrium ( M ) 2 − x + x 2 + x The equilibrium expression for the reaction is as shown below: K a = [CH 3 COO − ][H + ] [ CH 3 COOH ] Here, K a is the equilibrium constant. The concentrations of acetate ion, acetic acid, and hydrogen ion are represented by [ CH 3 COO − ] , [ CH 3 COOH ] , and [ H + ] , respectively. The acid dissociation constant of acetic acid is 1 .8 × 10 − 5 . The value of x is very small as compared to 2 and hence, it can be neglected. Substitute the values of the concentrations in the above expression as shown below, K a = [H + ](2 + x ) (2 .0 − x ) ≈ [ H + ] ( 2 ) ( 2 ) = [ H + ] Take minus log on both sides of the above expression. − log(K a ) = − log([H + ]) pK a = pH Substitute the value of the dissociation constant in the above expression, pH = − log ( 1.8 × 10 − 5 ) = 4.74 pH = 4.74 Hence, pH = 4.74 Another methodforcalculating the pH of a buffer solution isgiven by the Henderson–Hasselbalach equation. The expression for the pH for an acidic buffer is as follows: pH = pK a + log [Conjugate Base] [Weak Acid] pH = − log ( K a ) + log [2] [2] = − log ( 1.8 × 10 − 5 ) = 4.74 Hence, the pH of the solution has been calculated. b) 0.20 M acetic acid and 0.20 M sodium acetate Consider the degree of dissociation to be x

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ISBN: 9780078021527

Author: Julia Burdge

Publisher: McGraw-Hill Education

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Acid Base Titration

An acid-base titration is the method of quantitative analysis for determining the concentration of an acid and base by exactly neutralizing it with a standard solution of base or acid having known concentration.

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Chapter 17, Problem 10QP

Interpretation Introduction

Interpretation:

The pH for the given buffer solutions is to be calculated. Also, the more effective buffer and the reason for its effectiveness are to be determined.

Concept introduction:

Buffers are the solutionsthat resist the change in the pH on the addition of a few amounts of the acid and the alkali. It isa mixture of a weak acid with its conjugate base or a weak base with its conjugate acid.

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Chapter 17, Problem 9QP

Chapter 17, Problem 11QP

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(a) Calculate the pH of the 0.30 M NH3 / 0.35 M NH4Cl buffer. What is the pH of the buffer after the addition of 0.030 mol HCl? note: Ka (NH4+) = 5.6 x 10 -10 NH3 (aq) + H+ (aq) → NH4+ (aq) (b) What are the hydronium [H3O+] and hydroxide [OH-] ion concentrations at 25°C in a 4.0 M aqueous Mg(OH)2.

4) A highly toxic hydrogen cyanide (HCN) is a weak acid. A chemical engineer plans to determine pH of a 50 mL sample of HCN (0.10 M) in a titration process. To this end, she used 0.20 M NaOH as a titrant in varying volumes. Calculate the pH of the solution at the following points: (Ka for HCN=6.2×10-¹0) (a) Before addition of NaOH (initial pH), (b) After 10.00 mL of titrant addition, (c) After 25.00 mL of titrant addition, (d) After 50.00 mL of titrant addition.

Calculate the pH of a buffer solution made by mixing 300 mL of 0.3 M acetic acid, CH;COOH, and 200-mL of 0.2 M of its salt sodium acetate, CH3COONA, to make 500 mL of solution. Ka for CH3 COOH = 1.76x 10-5 O 4.4 O 5.0 6.3 O 3.4

Chapter 17 Solutions

Chemistry

Ch. 17.1 - Practice ProblemATTEMPT Determine the pH at 25°C...Ch. 17.1 - Practice ProblemBUILD Determine the pH at 25°C of...Ch. 17.1 - Prob. 1PPC Ch. 17.1 - Which of the following would cause a decrease in...Ch. 17.1 - What is the pH of a solution prepared by adding 0...Ch. 17.2 - Practice Problem ATTEMPT Calculate the pH of 1 L...Ch. 17.2 - Practice Problem BUILD How much must be added to...Ch. 17.2 - Practice Problem CONCEPTUALIZE The first diagram...Ch. 17.2 - 17.2.1 Which of the following combinations can be...Ch. 17.2 - What is the pH of a buffer that is 0.76 M in HF...

Ch. 17.2 - 17.2.3 Consider 1 L of a buffer that is 0.85 M in...Ch. 17.2 - Consider 1 L of a buffer that is 1.5 M in...Ch. 17.2 - The solutions shown contain one or more of the...Ch. 17.2 - Prob. 6CP Ch. 17.3 - Practice ProblemATTEMPT Select an appropriate acid...Ch. 17.3 - Prob. 1PPB Ch. 17.3 - Practice ProblemCONCEPTUALIZE The diagrams...Ch. 17.3 - 17.3.1 For which of the following titrations will...Ch. 17.3 - 17.3.2 Calculate the pH at the equivalence point...Ch. 17.3 - Prob. 3CP Ch. 17.3 - Calculate the pH after the addition of 35 mL of...Ch. 17.3 - Prob. 5CP Ch. 17.3 - Prob. 6CP Ch. 17.3 - Prob. 7CP Ch. 17.3 - Prob. 8CP Ch. 17.3 - Referring to the titration curve shown in Figure...Ch. 17.4 - Practice ProblemATTEMPT For the titration of 10.0...Ch. 17.4 - Practice ProblemBUILD For the titration of 25.0 mL...Ch. 17.4 - Prob. 1PPC Ch. 17.4 - Prob. 1CP Ch. 17.4 - Prob. 2CP Ch. 17.4 - Prob. 3CP Ch. 17.4 - Prob. 4CP Ch. 17.4 - Prob. 5CP Ch. 17.5 - Practice Problem ATTEMPT Calculate the pH at the...Ch. 17.5 - Practice Problem BUILD A 50.0-mL quantity of a...Ch. 17.5 - Prob. 1PPC Ch. 17.5 - 17.5.1 Calculate the molar solubility of AgCl in...Ch. 17.5 - Prob. 2CP Ch. 17.5 - Prob. 3CP Ch. 17.6 - Practice Problem ATTEMPT Referring to Table 17.3,...Ch. 17.6 - Practice Problem BUILD For which of the bases in...Ch. 17.6 - Practice Problem CONCEPTUALIZE The diagram shows...Ch. 17.6 - Prob. 1CP Ch. 17.6 - 17.6.2 Barium nitrate is added slowly to a...Ch. 17.7 - Prob. 1PPA Ch. 17.7 - Prob. 1PPB Ch. 17.7 - Prob. 1PPC Ch. 17.8 - Prob. 1PPA Ch. 17.8 - Prob. 1PPB Ch. 17.8 - Prob. 1PPC Ch. 17.9 - Prob. 1PPA Ch. 17.9 - Practice Problem BUILD What is the maximum mass...Ch. 17.9 - Prob. 1PPC Ch. 17.10 - Practice ProblemATTEMPT Calculate the molar...Ch. 17.10 - Practice ProblemBUILD Arrange the following salts...Ch. 17.10 - Practice Problem CONCEPTUALIZE The diagram on the...Ch. 17.11 - Practice Problem ATTEMPT Determine if the...Ch. 17.11 - Practice Problem BUILD Other than those in Sample...Ch. 17.11 - Practice Problem CONCEPTUALIZE If an ionic...Ch. 17.12 - Practice ProblemATTEMPT In the presence of aqueous...Ch. 17.12 - Prob. 1PPB Ch. 17.12 - Prob. 1PPC Ch. 17.13 - Practice ProblemATTEMPT Lead(II) nitrate is added...Ch. 17.13 - Prob. 1PPB Ch. 17.13 - Prob. 1PPC Ch. 17 - Which of the acids in Table 16.6 can be used to...Ch. 17 - What molar ratio of sodium cyanide to hydrocyanic...Ch. 17 - How many moles of sodium benzoate must be added to...Ch. 17 - How much sodium fluoride must be dissolved in 250...Ch. 17 - Use Le Châtelier’s principle to explain how the...Ch. 17 - 17.2 Describe the effect on pH (increase,...Ch. 17 - Prob. 3QP Ch. 17 - The p K a values of two monoprotic acids HA and HB...Ch. 17 - 17.5 Determine the pH of (a) a solution and (b) a...Ch. 17 - Determine the pH of (a) a 0 .20 M NH 3 solution,...Ch. 17 - Prob. 7QP Ch. 17 - Prob. 8QP Ch. 17 - Prob. 9QP Ch. 17 - Prob. 10QP Ch. 17 - Prob. 11QP Ch. 17 - 17.12 What is the pH of the buffer Ch. 17 - The pH of a sodium acetate-acetic acid buffer is...Ch. 17 - The pH of blood plasma is 7.40. Assuming the...Ch. 17 - 17.15 Calculate the pH of the buffer. What is the...Ch. 17 - 17.16 Calculate the of 1.00 L of the buffer ...Ch. 17 - Which of the following solutions can act as a...Ch. 17 - Which of the following solutions can act as a...Ch. 17 - A diprotic acid. H 2 A , has the following...Ch. 17 - Prob. 20QP Ch. 17 - 17.21 The following diagrams contain one or more...Ch. 17 - The following diagrams represent solutions...Ch. 17 - Briefly describe what happens in an acid-base...Ch. 17 - Prob. 24QP Ch. 17 - Explain how an acid-base indicator works in a...Ch. 17 - Prob. 26QP Ch. 17 - A 0.2688-g sample of a monoprotic acid neutralizes...Ch. 17 - Prob. 28QP Ch. 17 - 17.29 In a titration experiment, 12.5 mL of ...Ch. 17 - 17.30 In a titration experiment. 20.4 mL of 0.883...Ch. 17 - A 0.1276-g sample of an unknown monoprotic acid...Ch. 17 - Prob. 32QP Ch. 17 - Calculate the pH at the equivalence point for the...Ch. 17 - Calculate the pH at the equivalence point for the...Ch. 17 - 17.35 A 25.0-mL solution of 0.100 M is titrated...Ch. 17 - 17.36 A 10.0-ml solution of 0.300 M is titrated...Ch. 17 - Prob. 37QP Ch. 17 - Prob. 38QP Ch. 17 - 17.39 The ionization constant of an indicator is...Ch. 17 - The K a of a certain indicator is 2.0 × 10 − 6 ....Ch. 17 - 17.41 The following diagrams represent solutions...Ch. 17 - The following diagrams represent solutions at...Ch. 17 - Use BaS O 4 to distinguish between the terms...Ch. 17 - 17.44 Why do we usually not quote the values for...Ch. 17 - 17.45 Write balanced equations and solubility...Ch. 17 - 17.46 Write the solubility product expression for...Ch. 17 - How can we predict whether a precipitate will form...Ch. 17 - 17.48 Silver chloride has a larger than silver...Ch. 17 - 17.49 Calculate the concentration of ions in the...Ch. 17 - From the solubility data given, calculate the...Ch. 17 - The molar solubility of MnCO 3 is 4 .2 × 10 -6 M ....Ch. 17 - The solubility of an ionic compound MX ( molar...Ch. 17 - The solubility of an ionic compound M 2 X 3 (...Ch. 17 - Using data from Table 17.4, calculate the molar...Ch. 17 - What is the pH of a saturated zinc hydroxide...Ch. 17 - The pH of a saturated solution of a metal...Ch. 17 - If 20.0 mL of 0.10 M Ba ( NO 3 ) 2 is added to...Ch. 17 - 17.58 A volume of 75 mL of 0.060 M NaF is mixed...Ch. 17 - 17.59 How does the common ion effect influence...Ch. 17 - The molar solubility of AgCl in 6.5 × 10 − 3 M...Ch. 17 - 17.61 Give an example to illustrate the general...Ch. 17 - How many grams of CaCO 3 will dissolve in 3 .0 ×...Ch. 17 - The solubility product of PbBr 2 is 8 .9 × 10 -6 ....Ch. 17 - Calculate the molar solubility of AgCl in a 1.00-L...Ch. 17 - 17.65 Calculate the molar solubility of in (a)...Ch. 17 - Which of the following ionic compounds will be...Ch. 17 - Which of the following will be more soluble in...Ch. 17 - Compare the molar solubility of Mg ( OH ) 2 in...Ch. 17 - Calculate the molar solubility of Fe ( OH ) 2 in a...Ch. 17 - 17.70 The solubility product of . What minimum ...Ch. 17 - Calculate whether or not a precipitate will form...Ch. 17 - 17.72 If 2.50 g of is dissolved in what are the...Ch. 17 - Calculate the concentrations of Cd 2+ , Cd ( CN )...Ch. 17 - If NaOH is added to 0 .010 M Al 3+ . which will be...Ch. 17 - Calculate the molar solubility of AgI in a 1 .0 M...Ch. 17 - Both Ag - and Zn 2- form complex ions with NH 3 ....Ch. 17 - 17.77 Explain, with balanced ionic equations, why...Ch. 17 - Outline the general procedure of qualitative...Ch. 17 - Give two examples of metal ions m each group (1...Ch. 17 - Solid NaI is slowly added to a solution that is 0...Ch. 17 - Find the approximate pH range suitable for the...Ch. 17 - 17.82 In a group 1 analysis, a student obtained a...Ch. 17 - 17.83 In a group 1 analysis, a student adds acid...Ch. 17 - Both KCl and XH 4 Cl are white solids. Suggest one...Ch. 17 - Describe a simple test that would allow you to...Ch. 17 - 17.86 The buffer range is defined by the equation...Ch. 17 - The p K a of the indicator methyl orange is 3.46....Ch. 17 - 17.88 Sketch the titration curve of a weak acid...Ch. 17 - A 200-mL volume of KaOH solution was added to 400...Ch. 17 - 17.90 The of butyric acid (HBut) is 4.7....Ch. 17 - A solution is made by mixing exactly 500 mL of...Ch. 17 - The titration curve shown here represents the...Ch. 17 - Cd ( OH ) 2 is an insoluble compound. It dissolves...Ch. 17 - A student mixes 50 .0 mL of 1 .00 M Ba ( OH ) 2...Ch. 17 - For which of the following reactions is the...Ch. 17 - Water containing Ca 2+ and Mg 2+ ions is called...Ch. 17 - Equal volumes of 0 .12 M AgNO 3 and 0 .14 M ZnCl 2...Ch. 17 - Find the approxite pH range suitable for...Ch. 17 - 17.99 Calculate the solubility (in g/L) of Ch. 17 - 17.100 A volume of is titrated against a ...Ch. 17 - Prob. 101AP Ch. 17 - 17.102 When a KI solution was added to a solution...Ch. 17 - Which of the following compounds, when added to...Ch. 17 - The p K a of phenolphthalein is 9.10. Over what pH...Ch. 17 - Solid NaBr is slowly added to a solution that is...Ch. 17 - 17.106 Cacodylic acid is . Us ionization constant...Ch. 17 - Prob. 107AP Ch. 17 - Prob. 108AP Ch. 17 - Prob. 109AP Ch. 17 - CaSO 4 ( K sp = 2.4 × 10 − 5 ) has a larger K sp...Ch. 17 - Describe how you would prepare 1 − L0 .20 M CH 3...Ch. 17 - Phenolphthalein is the common indicator for the...Ch. 17 - Prob. 113AP Ch. 17 - 17.114 The molar mass of a certain metal...Ch. 17 - Consider the ionization of the following acid-base...Ch. 17 - One way to distinguish a buffer solution with an...Ch. 17 - 17.117 (a) Referring to Figure 17.4. describe how...Ch. 17 - AgNO 3 is added slowly to a solution that contains...Ch. 17 - The follwing diagrams represent solutions of MX,...Ch. 17 - 17.120 A 2.0-L kettle contains 116 g of boiler...Ch. 17 - 17.121 Radiochemical techniques are useful in...Ch. 17 - 17.122 One of the most common antibiotics is...Ch. 17 - 17.123 Barium is a toxic substance that can...Ch. 17 - 17.124 Tris [tris(hydroxymethyl)aminomethane] is a...Ch. 17 - Calcium oxalate is a major component of kidney...Ch. 17 - Histidine is one of the 20 amino acids found in...Ch. 17 - Amino acids are building blocks of proteins. These...Ch. 17 - 17.128 Oil paintings containing lead(II) compounds...Ch. 17 - 17.129 The maximum allowable concentration of ...Ch. 17 - Prob. 130AP Ch. 17 - When lemon juice is added to tea. the color...Ch. 17 - How many milliliters of 1.0 M NaOH must be added...Ch. 17 - Prob. 133AP Ch. 17 - Distribution curves show how the fractions of a...Ch. 17 - 17.135 A 1.0-L saturated silver carbonate solution...Ch. 17 - Draw distribution curves for an aqueous carbonic...Ch. 17 - 17.137 Acid-base reactions usually go to...Ch. 17 - Calculate x, the number of molecules of water in...Ch. 17 - Prob. 1SEPP Ch. 17 - Aqueous acid reacts with carbonate Jons to produce...Ch. 17 - Aqueous acid reacts with carbonate Jons to produce...Ch. 17 - Prob. 4SEPP

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Solution Summary: The author explains that buffers are solutions that resist the change in pH on the addition of a few amounts of the acid and the alkali.

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Chapter 17 Solutions