Chapter 17 Additional Aspects of Aqueous Equilibria (Part A)
|
|
- Lucas Hutchinson
- 5 years ago
- Views:
Transcription
1 Chapter 17 Additional Aspects of Aqueous Equilibria (Part A) Often, there are many equilibria going on in an aqueous solution. So, we must determine the dominant equilibrium (i.e. the equilibrium reaction that involves major species as reactants). Major species are present at relative high concentration, whereas minor species are present at much lower concentration. Reactions between acids and bases 1. Strong Acids + Strong Base The reaction goes to completion (products are neutral). HNO 3 + KOH H 2 O + KNO 3 Net: H 3 O + + HO 2H 2 O K = 1 K w = Weak Acid + Strong Base HC 2 H 3 O 2 + HO H 2 O + C 2 H 3 O 2 (reverse of K b reaction) K = 1 K b C2 H 3 O 2 = 1 = The reaction goes to completion (products are basic). 3. Strong Acid + Weak Base H 3 O + + NH 3 NH H 2 O (reverse of K a reaction) K = 1 K a NH4 + = 1 = The reaction goes to completion (products are acidic). 4. Weak Acid + Weak Base May or may not go to completion. Depends on K a, K b of the acid and base mixed. 1
2 17.1 The Common-Ion Effect Consider a solution of acetic acid: CH 3 COOH(aq) + H 2 O(l) H 3 O + (aq) + CH 3 COO (aq) Equilibrium shifts What would happen if acetate ion, CH 3 COONa(aq), is added to the solution? (Hint: Le Châtelier.) phacid by itself < phacid and common ion The acid ionizes less (than it normally would). The same effect is obtained if we add H3O + from another source (HCl, HBr, etc.). Common-ion effect. Q. Calculate the ph of a solution containing M nitrous acid (HNO2, Ka = ) and 0.10 M potassium nitrite (KNO2) Buffered Solutions A buffer solution contains a weak acid and its conjugate base (also weak); the ratio being between 1/10 and 10/1. Both HA and A are major species. A buffer solution is stable HA and A are in equilibrium with each other: HA + H 2 O H 3 O + + A 2
3 Buffers resist drastic ph changes when other acids or bases are added. If a strong acid is added: H 3 O + + A HA + H 2 O This uses up some A and produces some more HA. It changes the ratio of HA and A present, instead of affecting the ph directly. If a strong base is added: OH + HA H 2 O + A Converts some of the HA to A. Note: it is possible to overwhelm the buffer if you add too much strong acid or strong base. Finding the ph of a Buffer Due to the common ion effect, x s are always negligible. Initial [HA] = Equilibrium [HA] Initial [A ] = Equilibrium [A ] Check this assumption afterward (just in case). If it is not ok to make it, use successive approximations or solve the quadratic expression (your choice). For a buffer: K a = [H 3O + ][A ] [HA] Initial conc. = equilibrium conc. Since both HA and A are major species, you could use either the K a or the K b expression to solve. Important shortcut for a buffer (where x is negligible): K b = [HO ][HA] [A ] [A ] moles A = [HA] moles HA K a = [H 3 O + mol A ] mol HA K b = [OH ] mol HA mol A 3
4 Q. Calculate the ph of a buffer containing 0.10 mol H 2 PO 4 and 0.20 mol HPO 4 2 in 500. ml solution. Finding the ph of a Buffer Adding SA or SB to a buffer. 1. Complete reaction What s left? 2. Equilibrium. Q. If you have a buffer containing mol H 2 PO 4 and mol HPO 4 2 in 50.0 ml, what is the ph after adding 10.0 ml 0.10 M NaOH? 4
5 Henderson-Hasselbalch (HH) Equation It is used for buffers only. K a = [A ][H 3 O + ] [HA] ; [H 3 O + ] = K a ( [HA] [A ] ) log[h 3 O + ] = log K a ( [HA] [A ] ) log[h 3 O + ] = log K a + ( log ( [HA] [A ] )) ph = log K a + ( log ( [HA] [A ] )) ph = pk a + ( log ( [HA] [A ] )) ph = pk a + log ( [A ] [HA] ) Buffering Range A buffer will be effective when: 0.1 < [base]:[acid] < 10 Using the Henderson-Hasselbalch equation we have: Lowest ph ph = pk a + log(0.10) Highest ph ph = pk a + log(10) ph = pk a 1 ph = pk a + 1 Therefore, the effective ph range of a buffer is pka ± 1. When choosing an acid or base to make a buffer, choose one with its pka closest to the ph of the buffer. Example: Acetic Acid K a = ; pk a = The HC 2 H 3 O 2 /C 2 H 3 O 2 system can buffer in ph range of If [HA] = [A ] ; ratio = 1 ; log 1 = 0 Then ph = pk a (this is a special case). If [A ] > [HA] ; more conj base: ph > pk a If [HA] > [A ]; more conj acid: ph < pk a ph of a buffer depends on 1. pka of the acid, and 2. The ratio of [base]/[acid]. 5
6 Making a buffer of a specific ph: 1. Choose the buffer system (conjugate acid-base pair). We want a ratio [A ]/[HA] as close to 1 as possible; so the pka of the conjugate acid should be close to the desired ph, and no more than 1 unit away (remember the ratio?) If you want a buffer with a ph = 8.00, we want a K a value close to: [H + ] = We look at Appendix D (p. 1062). The buffer system is: HClO and ClO. HClO K a = ; pk a = Find the [A ]/[HA]. K a = [H 3O + ][ClO ] [HClO] ; K a [H 3 O + ] = [ClO ] [HClO] K a [H 3 O + ] Need 3.0 mol ClO for every 1.0 mol HClO. Could choose any amounts that fulfill this ratio ClO = = 3.0 = HClO However, if the amounts are too low, the buffer will not have a large buffer capacity (i.e. it will get used up too quickly and it won t be very resistant to ph changes). Examples: 1. Dissolve 3.0 mol NaClO and 1.0 mol HClO in 1 L H2O. 2. Mix 300 ml 0.10 M NaClO (aq) and 100 ml 0.10 M HClO. Etc. Other considerations (for the choice of a buffer) are: Solubility and Toxicity. Q. You want to make a buffer of ph = The following compounds are available: di water, Na 2 CO 3 (s), NaHCO 3 (s), 2.00 M NH 3, NH 4 Cl s. a. Which buffer system will you use? b. If you want the least concentrated buffer component to have a concentration = 0.20 M, how will you make 500. ml of this buffer? 6
7 Q. c. If you want a buffer of ph in which the least conc. component is 0.20 M, how will you make 500 ml of this buffer if available compounds are: di water, Na 2 CO 3 (s), 2.00 M HCl? 17.3 Acid Base Titrations If you know the volumes of both solutions used and the concentration of one of the solutions, you can calculate the concentration of the other solution using stoichiometry. Titrant is the substance of known concentration (added slowly); on the other hand, analyte is the substance of unknown concentration. 7
8 The equivalence point is the point at which the stoichiometric amount of analyte equals that of the titrant (in our case, the amount of acid equals that of base). Sometimes an indicator is used and the endpoint of the titration is found (when the indicator changes color). This point is related to the equivalence point, but is not the same. Titration Curve A plot of ph vs. amount of added titrant. The inflection point of the curve is the equivalence point of the titration. Prior to the equivalence point, the unknown solution in the flask is in excess, so the ph is closest to its ph. The ph of the equivalence point depends on the ph of the salt solution equivalence point of neutral salt, ph = 7 equivalence point of acidic salt, ph < 7 equivalence point of basic salt, ph > 7 Beyond the equivalence point, the known solution in the burette is in excess, so the ph approaches its ph 1. Titration of a SA with a SB Reaction: H 3 O + + OH 2H 2 O From the start of the titration to near the equivalence point, the ph goes up slowly. Just before (and after) the equivalence point, the ph increases rapidly. At the equivalence point, moles acid = moles base, and the solution contains only water and the salt from the cation of the base and the anion of the acid. (ph=7.00) As more base is added, the increase in ph again levels off. Q. If you start with 50.0 ml M HCl and add 40.0 ml NaOH, calculate the ph of the resulting solution. 8
9 Titration of a Strong Base with a Strong Acid If the titration is run so that the acid is in the burette and the base is in the flask, the titration curve will be the reflection of the one just shown 2. Titration of a WA with a SB Unlike in the previous case, the conjugate base of the acid affects the ph when it is formed. At the equivalence point the ph is >7. Phenolphthalein is commonly used as an indicator in these titrations. At the equivalence point, all HA has been converted to A (a Weak Base), so, the solution is basic (ph>7). Halfway point: half of the initial HA has been converted to A, and half HA remains. We can estimate the pk a from the graph. [HA] = [A ] ; K a = [H 3O + ][A ] [HA] ph = pk a (at this point) = [H 3 O + ] 9
10 Calculating ph at different points during a titration: 1. Consider complete reactions. 2. What is left? Consider equilibria. In the first region have HA. Consider Ka equilibrium (regular WA calculation). In the buffer region, use the buffer shortcut equation. Calculations The Buffer Region Q. What is the ph of the resulting solution if 25.0 ml of 0.10 M HF is mixed with 10.0 ml of 0.15 M NaOH? K a of HF = At the equivalence point Q. What is the ph at the equivalence point when 25.0 ml 0.10 M HF is titrated with 0.15 M NaOH? K a of HF =
11 Beyond the Equivalence Point The excess of OH determines the ph. Q. If 25.0 ml 0.10 M HF is mixed with 25.0 ml 0.15M NaOH, what is the ph? (K a HF = ) Titration of a Weak Acid with a Strong Base Final Notes With weaker acids, the initial ph is higher and ph changes near the equivalence point are more subtle. 3. Titration of a WB with a SA The ph at the equivalence point in these titrations is <7. Indicators Why would Phenolphthalein indicator wouldn t be a good choice for WB-SA titrations? Methyl red is the indicator of choice. ph Calculations 1. Initially there is just B. Use K b of B to calculate [OH ]. 2. Buffer region. Use buffer shortcut equation. 3. Equivalence point. Since we have BH +, we use K a and the reaction to calculate [H 3 O + ]. 4. Beyond the equivalence point, the ph is determined by the [H 3 O + ] in excess. 11
12 Q. Calculate the ph at the equivalence point in the titration of 25.0 ml of 0.20 M NH 3 with 0.20 M HNO 3. K b NH3 = Choosing an Indicator Usually a small amount of indicator is used, so it doesn t affect the ph of the solution. Nevertheless, the indicator responds to the ph of the solution. The indicator for a titration must change color within the steep part of the curve. So the pk a of the indicator should be close to the ph at the equivalence point. The endpoint of a titration (the point at which the indicator changes color) ideally corresponds to the equivalence point. For SA and SB titrations, the steep part of the curve corresponds to ph ~3 11. Many different indicators would work. WA/SB titration ph at the endpoint is basic. We need an indicator with a slightly basic K b. Phenolphthalein works (ph 8-10) Methyl red doesn t (ph 4-6) WB/SA ph at the endpoint is acidic Methyl red works, but phenolpthalein doesn t. 12
13 Titrations of Polyprotic Acids When one titrates a polyprotic acid with a base there is an equivalence point for each dissociation. Note: the closer the Ka s are to each other, the less distinguishable the equivalence points are More Practice Problems Q. Aniline: C 6 H 5 NH 2 K b = dimethylamine (CH 3 ) 2 NH 2 K b = pyridine C 5 H 5 N K b = trimethylamine(ch 3 ) 3 NK b = If you want a buffer at ph 5.60 a. Which is the best choice? b. What is the buffer system? c. What could you add to the WB to make the buffer? Q. You have a buffer containing H 3 BO 3 and H 2 BO 3, in which the ratio of H 2 BO 3 /H 3 BO 3 is 0.5 (or ½). K a = a. Is this buffer acidic or basic? b. Will the ph of this buffer be greater than, less than, or equal to 9.23? 13
14 c. What is the ph of this buffer? d. You have 800. ml of this buffer. [H 2 BO 3 ] = 0.20 M in the buffer. What volume of 2.00 M NaOH or 2.00 M HCl is needed to change the ph to 9.50? e. What mass of H 3 BO 3 (s) or NaH 2 BO 3 (s) is needed to change the ph of he original buffer to 9.50? 14
Chapter 17 Additional Aspects of Aqueous Equilibria (Part A)
Chapter 17 Additional Aspects of Aqueous Equilibria (Part A) What is a dominant equilibrium? How do we define major species? Reactions between acids and bases 1. Strong Acids + Strong Base The reaction
More informationACID-BASE REACTIONS. Titrations Acid-Base Titrations
Page III-b-1 / Chapter Fourteen Part II Lecture Notes ACID-BASE REACTIONS Chapter (Part II A Weak Acid + Strong Base Titration Titrations In this technique a known concentration of base (or acid is slowly
More informationChapter 17. Additional Aspects of Aqueous Equilibria. Lecture Presentation. John D. Bookstaver St. Charles Community College Cottleville, MO
Lecture Presentation Chapter 17 Additional Aspects of John D. Bookstaver St. Charles Community College Cottleville, MO The Common-Ion Effect Consider a solution of acetic acid: CH 3 COOH(aq) + H 2 O(l)
More informationAcid-Base Equilibria. And the beat goes on Buffer solutions Titrations
Acid-Base Equilibria And the beat goes on Buffer solutions Titrations 1 Common Ion Effect The shift in equilibrium due to addition of a compound having an ion in common with the dissolved substance. 2
More informationChapter 15. Acid-Base Equilibria
Chapter 15 Acid-Base Equilibria The Common Ion Effect The common-ion effect is the shift in an ionic equilibrium caused by the addition of a solute that provides an ion already involved in the equilibrium
More informationLecture #11-Buffers and Titrations The Common Ion Effect
Lecture #11-Buffers and Titrations The Common Ion Effect The Common Ion Effect Shift in position of an equilibrium caused by the addition of an ion taking part in the reaction HA(aq) + H2O(l) A - (aq)
More informationLecture 12. Acid/base reactions. Equilibria in aqueous solutions.
Lecture 12 Acid/base reactions. Equilibria in aqueous solutions. Titrations Kotz 7 th ed. Section 18.3, pp.821-832. In a titration a solution of accurately known concentration is added gradually added
More informationThe ph of aqueous salt solutions
The ph of aqueous salt solutions Sometimes (most times), the salt of an acid-base neutralization reaction can influence the acid/base properties of water. NaCl dissolved in water: ph = 7 NaC 2 H 3 O 2
More informationAqueous Equilibria Pearson Education, Inc. Mr. Matthew Totaro Legacy High School AP Chemistry
2012 Pearson Education, Inc. Mr. Matthew Totaro Legacy High School AP Chemistry The Common-Ion Effect Consider a solution of acetic acid: HC 2 H 3 O 2 (aq) + H 2 O(l) H 3 O + (aq) + C 2 H 3 O 2 (aq) If
More informationChapter 17 Additional Aspects of
Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 17 Additional Aspects of AP Chemistry 2014-15 North Nova Education Centre Mr. Gauthier
More informationKotz 7 th ed. Section 18.3, pp
Lecture 15 Acid/base reactions. Equilibria in aqueous solutions. Titrations Kotz 7 th ed. Section 18.3, pp.821-832. In a titration a solution of accurately known concentration is added gradually added
More informationChapter 17 Additional Aspects of
Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 17 Additional Aspects of John D. Bookstaver St. Charles Community College Cottleville,
More informationCh. 17 Applications of Aqueous Equilibria: Buffers and Titrations
Ch. 17 Applications of Aqueous Equilibria: Buffers and Titrations Sec 1 The Common-Ion Effect: The dissociation of a weak electrolyte decreases when a strong electrolyte that has an ion in common with
More informationHomework #7 Chapter 8 Applications of Aqueous Equilibrium
Homework #7 Chapter 8 Applications of Aqueous Equilibrium 15. solution: A solution that resists change in ph when a small amount of acid or base is added. solutions contain a weak acid and its conjugate
More informationChapter 17: Additional Aspects of Aqueous equilibria. Common-ion effect
Chapter 17: Additional Aspects of Aqueous equilibria Learning goals and key skills: Describe the common ion effect. Explain how a buffer functions. Calculate the ph of a buffer solution. Calculate the
More informationLecture Presentation. Chapter 16. Aqueous Ionic Equilibrium. Sherril Soman Grand Valley State University Pearson Education, Inc.
Lecture Presentation Chapter 16 Aqueous Ionic Equilibrium Sherril Soman Grand Valley State University The Danger of Antifreeze Each year, thousands of pets and wildlife species die from consuming antifreeze.
More informationChapter 17 Additional Aspects of
Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; and Bruce E. Bursten Chapter 17 Additional Aspects of John D. Bookstaver St. Charles Community College Cottleville,
More informationReview: Acid-Base Chemistry. Title
Review: Acid-Base Chemistry Title Basics General properties of acids & bases Balance neutralization equations SA + SB water + salt Arrhenius vs. Bronsted-Lowry BL plays doubles tennis match with H+) Identify
More informationADVANCED PLACEMENT CHEMISTRY ACIDS, BASES, AND AQUEOUS EQUILIBRIA
ADVANCED PLACEMENT CHEMISTRY ACIDS, BASES, AND AQUEOUS EQUILIBRIA Acids- taste sour Bases(alkali)- taste bitter and feel slippery Arrhenius concept- acids produce hydrogen ions in aqueous solution while
More informationChem Chapter 18: Sect 1-3 Common Ion Effect; Buffers ; Acid-Base Titrations Sect 4-5 Ionic solubility Sect 6-7 Complex Formation
Chem 106 3--011 Chapter 18: Sect 1-3 Common Ion Effect; Buffers ; Acid-Base Titrations Sect 4-5 Ionic solubility Sect 6-7 Complex Formation 3//011 1 The net ionic equation for the reaction of KOH(aq) and
More informationApplications of Aqueous Equilibria Chapter 15. Titration Curves & Indicators Sections 4-5
Applications of Aqueous Equilibria Chapter 15 Titration Curves & Indicators Sections 45 Strong Acid vs. Strong Base Titration Titrate 50.0 ml of 0.200 M HNO 3 with 0.100 M NaOH What is the ph when no NaOH
More informationChapter 10. Acids, Bases, and Salts
Chapter 10 Acids, Bases, and Salts Topics we ll be looking at in this chapter Arrhenius theory of acids and bases Bronsted-Lowry acid-base theory Mono-, di- and tri-protic acids Strengths of acids and
More informationChap 17 Additional Aspects of Aqueous Equilibria. Hsu Fu Yin
Chap 17 Additional Aspects of Aqueous Equilibria Hsu Fu Yin 1 17.1 The Common-Ion Effect Acetic acid is a weak acid: CH 3 COOH(aq) H + (aq) + CH 3 COO (aq) Sodium acetate is a strong electrolyte: NaCH
More informationLecture 8. Making a Buffer. Buffers. Professor Hicks Inorganic Chemistry (CHE152)
Lecture 8 Professor Hicks Inorganic Chemistry (CHE152) Making a Buffer Buffers buffers = solutions that resist ph changes act by neutralizing added acid or base made by preparing a solution of a weak acid/base
More informationAcid Base Equilibria
Acid Base Equilibria Acid Ionization, also known as acid dissociation, is the process in where an acid reacts with water to produce a hydrogen ion and the conjugate base ion. HC 2 H 3 O 2(aq) H + (aq)
More informationChapter 17. Additional Aspects of Aqueous Equilibria. Lecture Presentation. James F. Kirby Quinnipiac University Hamden, CT
Lecture Presentation Chapter 17 Additional Aspects of James F. Kirby Quinnipiac University Hamden, CT Effect of Acetate on the Acetic Acid Equilibrium Acetic acid is a weak acid: CH 3 COOH(aq) H + (aq)
More informationChapter 14 Acid- Base Equilibria Study Guide
Chapter 14 Acid- Base Equilibria Study Guide This chapter will illustrate the chemistry of acid- base reactions and equilibria, and provide you with tools for quantifying the concentrations of acids and
More informationBuffers/Titration Aqueous Equilibria - I
Slide 1 / 113 Slide 2 / 113 uffers/titration queous Equilibria - I Review hydrolysis of salts Slide 3 / 113 1 The hydrolysis of a salt of a weak base and a strong acid should give a solution that is. Slide
More informationAdvanced Placement Chemistry Chapters Syllabus
As you work through the chapter, you should be able to: Advanced Placement Chemistry Chapters 14 16 Syllabus Chapter 14 Acids and Bases 1. Describe acid and bases using the Bronsted-Lowry, Arrhenius, and
More informationThe Common Ion Effect
Chapter 17 ACID BASE EQUILIBRIA (Part I) Dr. Al Saadi 1 17.1 The Common Ion Effect A phenomenon known as the common ion effect states that: When a compound containing an ion in common with an already dissolved
More informationChapter 16 Aqueous Ionic Equilibrium
Chemistry: A Molecular Approach, 1 st Ed. Nivaldo Tro Chapter 16 Aqueous Ionic Equilibrium Roy Kennedy Massachusetts Bay Community College Wellesley Hills, MA 2008, Prentice Hall The Danger of Antifreeze
More informationAP Chapter 15 & 16: Acid-Base Equilibria Name
AP Chapter 15 & 16: Acid-Base Equilibria Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8. AP Chapter 15 & 16: Acid-Base Equilibria 2 Warm-Ups (Show
More informationUnderstanding the shapes of acid-base titration curves AP Chemistry
Understanding the shapes of acidbase titration curves AP Chemistry Neutralization Reactions go to Completion Every acidbase reaction produces another acid and another base. A neutralization reaction is
More informationAdditional Aspects of Aqueous Equilibria David A. Katz Department of Chemistry Pima Community College
Additional Aspects of Aqueous Equilibria David A. Katz Department of Chemistry Pima Community College The Common Ion Effect Consider a solution of acetic acid: HC 2 H 3 O 2(aq) + H 2 O (l) H 3 O + (aq)
More informationConsider a normal weak acid equilibrium: Which direction will the reaction shift if more A is added? What happens to the % ionization of HA?
ch16blank Page 1 Chapter 16: Aqueous ionic equilibrium Topics in this chapter: 1. Buffers 2. Titrations and ph curves 3. Solubility equilibria Buffersresist changes to the ph of a solution. Consider a
More informationAcid and Base Titrations - Equation Guide
Acid and Base Titrations - Equation Guide Strong Acid + Strong Base: Initial Region: ph = - log (n sa / V sa ) or ph = - log (C sa ) Pre-Equivalence Region: ph = - log sa # or ph = - log Equivalence: ph
More information= ) = )
Basics of calculating ph 1. Find the ph of 0.07 M HCl. 2. Find the ph of 0.2 M propanoic acid (K a = 10-4.87 ) 3. Find the ph of 0.4 M (CH 3 ) 3 N (K b = 10-4.20 ) 4. Find the ph of 0.3 M CH 3 COO - Na
More informationBuffer Solutions. Buffer Solutions
Buffer Solutions A buffer solution is comprised of a mixture of an acid (base) with its conjugate base (acid) that resists changes in ph when additional acid or base is added The Henderson-Hasselbalch
More informationAP Chemistry: Acid-Base Chemistry Practice Problems
Name AP Chemistry: Acid-Base Chemistry Practice Problems Date Due Directions: Write your answers to the following questions in the space provided. For problem solving, show all of your work. Make sure
More informationAP Chemistry. CHAPTER 17- Buffers and Ksp 17.1 The Common Ion Effect Buffered Solutions. Composition and Action of Buffered Solutions
AP Chemistry CHAPTER 17- Buffers and Ksp 17.1 The Common Ion Effect The dissociation of a weak electrolyte is decreased by the addition of a strong electrolyte that has an ion in common with the weak electrolyte.
More informationChapter 8: Applications of Aqueous Equilibria
Chapter 8: Applications of Aqueous Equilibria 8.1 Solutions of Acids or Bases Containing a Common Ion 8.2 Buffered Solutions 8.3 Exact Treatment of Buffered Solutions 8.4 Buffer Capacity 8.5 Titrations
More informationTitration of a Weak Acid with a Strong Base
Titration of a Weak Acid with a Strong Base Weak Acid w/ Strong Base Overall: INITIAL ph: Weak acids do not fully dissociate we need to do an ICE table to determine initial ph. We expect it to be weakly
More informationChapter 15. Acid-Base Equilibria
Chapter 15 Acid-Base Equilibria Section 15.1 Solutions of Acids or Bases Containing a Common Ion Common Ion Effect Shift in equilibrium position that occurs because of the addition of an ion already involved
More informationHomework: 14, 16, 21, 23, 27, 29, 39, 43, 48, 49, 51, 53, 55, 57, 59, 67, 69, 71, 77, 81, 85, 91, 93, 97, 99, 104b, 105, 107
Homework: 14, 16, 21, 23, 27, 29, 39, 43, 48, 49, 51, 53, 55, 57, 59, 67, 69, 71, 77, 81, 85, 91, 93, 97, 99, 104b, 105, 107 Chapter 15 Applications of Aqueous Equilibria (mainly acid/base & solubility)
More informationAcid-Base Equilibria (Chapter 10.) Problems: 2,3,6,13,16,18,21,30,31,33
Acid-Base Equilibria (Chapter 10.) Problems: 2,3,6,13,16,18,21,30,31,33 Review acid-base theory and titrations. For all titrations, at the equivalence point, the two reactants have completely reacted with
More informationPart One: Pure Solutions of Weak Acids, Bases (water plus a single electrolyte solute)
CHAPTER 16: ACID-BASE EQUILIBRIA Part One: Pure Solutions of Weak Acids, Bases (water plus a single electrolyte solute) A. Weak Monoprotic Acids. (Section 16.1) 1. Solution of Acetic Acid: 2. See Table
More informationExample 15.1 Identifying Brønsted Lowry Acids and Bases and Their Conjugates
Example 15.1 Identifying Brønsted Lowry Acids and Bases and Their Conjugates For Practice 15.1 In each reaction, identify the Brønsted Lowry acid, the Brønsted Lowry base, the conjugate acid, and the conjugate
More informationCh. 14/15: Acid-Base Equilibria Sections 14.6, 14.7, 15.1, 15.2
Ch. 14/15: Acid-Base Equilibria Sections 14.6, 14.7, 15.1, 15.2 Creative Commons License Images and tables in this file have been used from the following sources: OpenStax: Creative Commons Attribution
More informationChapter 16. Equilibria in Aqueous Systems
Chapter 16 Equilibria in Aqueous Systems Buffers! buffers are solutions that resist changes in ph when an acid or base is added! they act by neutralizing the added acid or base! but just like everything
More information16.3 Weak Acids Weak Bases Titration
16.3 Weak Acids Weak Bases Titration Titration of Weak Acid with Strong Base Titration of Base Acid with Strong Acid Dr. Fred Omega Garces Chemistry 201 Miramar College 1 Weak Acids Weak Bases Titration
More informationAcid-Base Equilibria. 1.NH 4 Cl 2.NaCl 3.KC 2 H 3 O 2 4.NaNO 2. Acid-Ionization Equilibria. Acid-Ionization Equilibria
Acid-Ionization Equilibria Acid-Base Equilibria Acid ionization (or acid dissociation) is the reaction of an acid with water to produce hydronium ion (hydrogen ion) and the conjugate base anion. (See Animation:
More informationACID-BASE EQUILIBRIA. Chapter 14 Big Idea Six
ACID-BASE EQUILIBRIA Chapter 14 Big Idea Six Acid-Base Equilibria Common Ion Effect in Acids and Bases Buffer SoluDons for Controlling ph Buffer Capacity ph-titradon Curves Acid-Base TitraDon Indicators
More informationph calculations MUDr. Jan Pláteník, PhD Brønsted-Lowry concept of acids and bases Acid is a proton donor Base is a proton acceptor
ph calculations MUDr. Jan Pláteník, PhD Brønsted-Lowry concept of acids and bases Acid is a proton donor Base is a proton acceptor HCl(aq) + H 2 O(l) H 3 O + (aq) + Cl - (aq) Acid Base Conjugate acid Conjugate
More informationChapter 15 Acid Base Equilibria
Buffer Solutions The ph changes by a large amount even when a small amount of acid or base is added to pure water: Chapter 15 Acid Base Equilibria A buffer solution is a solution which resists a change
More informationChapter 17. Additional Aspects of Equilibrium
Chapter 17. Additional Aspects of Equilibrium 17.1 The Common Ion Effect The dissociation of a weak electrolyte is decreased by the addition of a strong electrolyte that has an ion in common with the weak
More informationChapter 17. Additional Aspects of Aqueous Equilibria 蘇正寬 Pearson Education, Inc.
Chapter 17 Additional Aspects of Aqueous Equilibria 蘇正寬 chengkuan@mail.ntou.edu.tw Additional Aspects of Aqueous Equilibria 17.1 The Common-Ion Effect 17.2 Buffers 17.3 Acid Base Titrations 17.4 Solubility
More informationChapter 16 Aqueous Ionic Equilibrium Buffer Solutions
Chapter 16 Aqueous Ionic Equilibrium 16.1-16.2 Buffer Solutions Why? While a weak acid will partially ionize to produce its conjugate base, it will not produce enough conjugate base to be considered a
More informationChapter 15 Acid-Base Equilibria
Chapter 15 Acid-Base Equilibria Acid-Base Equilibria 15.1 Solutions of Acids or Bases Containing a Common Ion A. Common Ion 1. Ion provided in solution by an aqueous acid (or base) as well as a salt a.
More informationAcid-Base Solutions - Applications
Acid-Base Solutions - Applications 1 The Common Ion Effect Consider the equilibrium established when acetic acid, HC 2 H 3 O 2, is added to water. CH 3 COOH(aq) + H 2 O(l) CH 3 COO - (aq) + H 3 O + (aq)
More informationAP CHEMISTRY NOTES 10-1 AQUEOUS EQUILIBRIA: BUFFER SYSTEMS
AP CHEMISTRY NOTES 10-1 AQUEOUS EQUILIBRIA: BUFFER SYSTEMS THE COMMON ION EFFECT The common ion effect occurs when the addition of an ion already present in the system causes the equilibrium to shift away
More informationAcids And Bases. H + (aq) + Cl (aq) ARRHENIUS THEORY
Acids And Bases A. Characteristics of Acids and Bases 1. Acids and bases are both ionic compounds that are dissolved in water. Since acids and bases both form ionic solutions, their solutions conduct electricity
More informationBuffer Effectiveness 19
Buffer Effectiveness 19 Buffer Effectiveness What makes a buffer effective? A buffer should be able to neutralize small to moderate amounts of added acid or base Too much added acid or base will destroy
More informationAcid-Base Equilibria. 1.NH 4 Cl 2.NaCl 3.KC 2 H 3 O 2 4.NaNO 2. Solutions of a Weak Acid or Base
Acid-Base Equilibria 1 Will the following salts be acidic, basic or neutral in aqueous solution? 1.NH 4 Cl.NaCl.KC H O 4.NaNO A = acidic B = basic C = neutral Solutions of a Weak Acid or Base The simplest
More informationChapter 15 - Applications of Aqueous Equilibria
Neutralization: Strong Acid-Strong Base Chapter 15 - Applications of Aqueous Equilibria Molecular: HCl(aq) + NaOH(aq) NaCl(aq) + H 2 O(l) SA-SB rxn goes to completion (one-way ) Write ionic and net ionic
More informationUnit 2 Acids and Bases
Unit 2 Acids and Bases 1 Topics Properties / Operational Definitions Acid-Base Theories ph & poh calculations Equilibria (Kw, K a, K b ) Indicators Titrations STSE: Acids Around Us 2 Operational Definitions
More informationGrade A buffer: is a solution that resists changes in its ph upon small additions of acid or base.sq1
Chapter 15 Lesson Plan Grade 12 402. The presence of a common ion decreases the dissociation. BQ1 Calculate the ph of 0.10M CH 3 COOH. Ka = 1.8 10-5. [H + ] = = ( )( ) = 1.34 10-3 M ph = 2.87 Calculate
More informationChem 1102 Semester 1, 2011 ACIDS AND BASES
Chem 1102 Semester 1, 2011 ACIDS AND BASES Acids and Bases Lecture 23: Weak Acids and Bases Calculations involving pk a and pk b Strong Acids and Bases Lecture 24: Polyprotic Acids Salts of Acids and Bases
More informationChemical Equilibrium
Chemical Equilibrium Many reactions are reversible, i.e. they can occur in either direction. A + B AB or AB A + B The point reached in a reversible reaction where the rate of the forward reaction (product
More informationUnit 4: ACIDS, BASES AND SALTS
ABS - 1 Unit 4: ACIDS, BASES AND SALTS 4.1 Arrhenius Acids and Bases Acids release H + in water Bases release OH - in water Salts are products of an acid-base neutralization reaction. The salt is an ionic
More informationTry this one Calculate the ph of a solution containing M nitrous acid (Ka = 4.5 E -4) and 0.10 M potassium nitrite.
Chapter 17 Applying equilibrium 17.1 The Common Ion Effect When the salt with the anion of a is added to that acid, it reverses the dissociation of the acid. Lowers the of the acid. The same principle
More informationChapter 17. Additional Aspects of Equilibrium
Chapter 17. Additional Aspects of Equilibrium 17.1 The Common Ion Effect The dissociation of a weak electrolyte is decreased by the addition of a strong electrolyte that has an ion in common with the weak
More informationAcids and Bases Written Response
Acids and Bases Written Response January 1999 4. Consider the salt sodium oxalate, Na2C2O4. a) Write the dissociation equation for sodium oxalate. (1 mark) b) A 1.0M solution of sodium oxalate turns pink
More informationBuffer solutions Strong acids and bases dissociate completely and change the ph of a solution drastically. Buffers are solutions that resist changes i
18.3 ph Curves Buffer solutions Strong acids and bases dissociate completely and change the ph of a solution drastically. Buffers are solutions that resist changes in ph even when acids and bases are added
More informationChapter 10. Acids and Bases
Chapter 10 Acids and Bases 1 Properties of Aqueous Solutions of Acids and Bases Aqueous acidic solutions have the following properties: 1. They have a sour taste.. They change the colors of many indicators.
More informationChem 106 Thursday, March 10, Chapter 17 Acids and Bases
Chem 106 Thursday, March 10, 2011 Chapter 17 Acids and Bases K a and acid strength Acid + base reactions: Four types (s +s, s + w, w + s, and w + w) Determining K from concentrations and ph ph of aqueous
More informationAcid-Base Equilibria. Contents and Concepts. Learning Objectives
Acid-Base Equilibria Contents and Concepts Solutions of a Weak Acid or Base 1. Acid-Ionization Equilibria. Polyprotic Acids 3. Base-Ionization Equilibria 4. Acid Base Properties of Salt Solutions Solutions
More informationAcids, Bases and Buffers
1 Acids, Bases and Buffers Strong vs weak acids and bases Equilibrium as it relates to acids and bases ph scale: [H+(aq)] to ph, poh, etc ph of weak acids ph of strong acids Conceptual about oxides (for
More informationAcid-Base Titration Solution Key
Key CH3NH2(aq) H2O(l) CH3NH3 (aq) OH - (aq) Kb = 4.38 x 10-4 In aqueous solution of methylamine at 25 C, the hydroxide ion concentration is 1.50 x 10-3 M. In answering the following, assume that temperature
More informationPoint: In an unbuffered, unprotected solution, a small addition of strong acid or base can cause a massive and dangerous shift in ph.
hem 210 Jasperse h 17 Handouts 1 h. 17 Additional Aqueous quilibria hapter 16 situations basically only involved one solute: strong or weak acid; strong or weak base; or ionic salt Real solutions often
More informationBuffers. A buffered solution resists changes in ph when small amounts of acids or bases are added or when dilution occurs.
Buffers A buffered solution resists changes in ph when small amounts of acids or bases are added or when dilution occurs. The buffer consists of a mixture of an acid and its conjugate base. Example: acetic
More informationFormation of a salt (ionic compound): Neutralization reaction. molecular. Full ionic. Eliminate spect ions to yield net ionic
Formation of a salt (ionic compound): Neutralization reaction molecular Full ionic Eliminate spect ions to yield net ionic Hydrolysis/ reaction with water Anions of Weak Acids Consider the weak acid HF
More informationIB Chemistry ABS Introduction An acid was initially considered a substance that would produce H + ions in water.
IB Chemistry ABS Introduction An acid was initially considered a substance that would produce H + ions in water. The Brønsted-Lowry definition of an acid is a species that can donate an H + ion to any
More informationACIDS AND BASES. HCl(g) = hydrogen chloride HCl(aq) = hydrochloric acid HCl(g) H + (aq) + Cl (aq) ARRHENIUS THEORY
ACIDS AND BASES A. CHARACTERISTICS OF ACIDS AND BASES 1. Acids and bases are both ionic compounds that are dissolved in water. Since acids and bases both form ionic solutions, their solutions conduct electricity
More informationHALFWAY to EQUIVALENCE POINT: ph = pk a of the acid being titrated.
CHEMISTRY 109 Help Sheet #33 Titrations Chapter 15 (Part II); Section 15.2 ** Cover topics appropriate for your lecture** Prepared by Dr. Tony Jacob http://www.chem.wisc.edu/areas/clc (Resource page) Nuggets:
More informationChapter 17 Answers. Practice Examples [H3O ] 0.018M, 1a. HF = M. 1b. 30 drops. 2a.
Chapter 17 Answers Practice Examples 1a. + [HO ] 0.018M, 1b. 0 drops [HF] = 0.8 M. [H O + ] = 0.10 M, HF = 0.97 M. a. + HO 1.10 M, CHO = 0.150 M. b. 15g NaCHO a. The hydronium ion and the acetate ion react
More informationChemistry 132 NT. Acid-Base Equilibria
Chemistry 132 NT Instead of having answers on a math test, they should just call them impressions, and if you got a different impression, so what, can t we all be brothers? Jack Handey 1 2 Chem 132 NT
More informationCHAPTER 8: ACID/BASE EQUILIBRIUM
CHAPTER 8: ACID/BASE EQUILIBRIUM Already mentioned acid-base reactions in Chapter 6 when discussing reaction types. One way to define acids and bases is using the Brønsted-Lowry definitions. A Brønsted-Lowry
More informationCHAPTER FIFTEEN APPLICATIONS OF AQUEOUS EQUILIBRIA. For Review
CHAPTER FIFTEEN APPLICATIONS OF AQUEOUS EQUILIBRIA For Review 1. A common ion is an ion that appears in an equilibrium reaction but came from a source other than that reaction. Addition of a common ion
More informationAcids and Bases. Reviewing Vocabulary CHAPTER ASSESSMENT CHAPTER 19. Compare and contrast each of the following terms.
Acids and Bases Reviewing Vocabulary Compare and contrast each of the following terms. 1. Arrhenius model, Brønsted-Lowry model 2. acid ionization constant, base ionization constant 3. conjugate acid,
More informationChapter 16: Applications of Aqueous Equilibrium Part 2. Acid-Base Titrations
Chapter 16: Applications of Aqueous Equilibrium Part 2 Acid-Base Titrations When you add an acid and a base together, a neutralization rxn occurs. In the lab, we do neutralization rxns all the time as
More informationCHM 112 Dr. Kevin Moore
CHM 112 Dr. Kevin Moore Reaction of an acid with a known concentration of base to determine the exact amount of the acid Requires that the equilibrium of the reaction be significantly to the right Determination
More informationJudith Herzfeld 1996,1998. These exercises are provided here for classroom and study use only. All other uses are copyright protected.
Judith Herzfeld 1996,1998 These exercises are provided here for classroom and study use only. All other uses are copyright protected. 3.3-010 According to Bronsted-Lowry Theory, which of the following
More informationCHEM Dr. Babb s Sections Exam #3 Review Sheet
CHEM 116 Dr. Babb s Sections Exam #3 Review Sheet Acid/Base Theories and Conjugate AcidBase Pairs 111. Define the following terms: Arrhenius acid, Arrhenius base, Lewis acid, Lewis base, BronstedLowry
More informationA 95 g/mol B 102 /mol C 117 g/mol D 126 g/mol E 152 g/mol
Titrations In a titration a solution of accurately known concentration is added gradually added to another solution of unknown concentration until the chemical reaction between the two solutions is complete.
More informationCHAPTER 7 Acid Base Equilibria
1 CHAPTER 7 Acid Base Equilibria Learning Objectives Acid base theories Acid base equilibria in water Weak acids and bases Salts of weak acids and bases Buffers Logarithmic concentration diagrams 2 ACID
More informationLast week, we discussed the Brønsted Lowry concept of acids and bases. According to this model:
Last week, we discussed the Brønsted Lowry concept of acids and bases This model is not limited to aqueous solutions; it can be extended to reactions in the gas phase! According to this model: Acids are
More informationAcid-Base Equilibria and Solubility Equilibria
Acid-Base Equilibria and Solubility Equilibria Acid-Base Equilibria and Solubility Equilibria Homogeneous versus Heterogeneous Solution Equilibria (17.1) Buffer Solutions (17.2) A Closer Look at Acid-Base
More informationChemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten; Catherine J. Murphy.
Chemistry, The Central Science, 11th edition Theodore L. Brown; H. Eugene LeMay, Jr.; Bruce E. Bursten; Catherine J. Murphy Chapter 17 Additional Aspects of Aqueous Equilibria Ahmad Aqel Ifseisi Assistant
More informationChapter 17. Additional Aspects of Equilibrium
Chapter 17. Additional Aspects of Equilibrium Sample Exercise 17.1 (p. 726) What is the ph of a 0.30 M solution of acetic acid? Be sure to use a RICE table, even though you may not need it. (2.63) What
More informationANALYTICAL CHEMISTRY - CLUTCH 1E CH.8 - MONOPROTIC ACID-BASE EQUILIBRIA.
!! www.clutchprep.com CONCEPT: ARRHENIUS ACIDS AND BASES The most general definition for acids and bases was developed by Svante Arrhenius near the end of the 19 th century. According to him, the cation
More information