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Key Concepts PowerPoint

Chapter 16
Applications of Aqueous Equilibria

  
16-02
Title
 The common-ion effect
Caption
 Figure 16.2 The common-ion effect. The concentration of H3O+in a 0.10 M acetic acid solution decreases as the concentration of added sodium acetate increases because added acetate ions shift the acid-dissociation equilibrium to the left. Note that [H3O+] is plotted on a logarithmic scale.
Notes
 The common-ion effect
Keywords
 common-ion effect
16-02-01UN
Title
 Key Concept Problem 16.3
Caption
 The following pictures represent solutions of a weak acid HA that may also contain the sodium salt NaA. Which solution has the highest pH, and which has the largest percent dissociation of HA?
Notes
 Key concept problem 16.3
Keywords
 common-ion effect
16-02-02UN
Title
 Key Concept Problem 16.5
Caption
 The following pictures represent solutions of a weak base B that may also contain the chloride salt BH+Cl-. Which solution has the lowest pH, and which has the largest percent dissociation of B?
Notes
 Key concept problem 16.5
Keywords
 common-ion effect
16-03
Title
 Buffer solutions
Caption
 Figure 16.3 (a) When OH-is added to a buffer solution, some of the weak acid is neutralized and thus converted to the conjugate base. (b) When H3O+is added to a buffer solution, some of the conjugate base is neutralized and thus converted to the weak acid. However, as long as the concentration ratio [weak acid]/[conjugate base] stays close to its original value, [H3O+] and the pH won’t change very much.
Notes
 Effect of additional acid or base on the pH of a buffer solution
Keywords
 buffers
16-04-01UN
Title
 Key Concept Problem 16.6
Caption
 The following pictures represent solutions that contain a weak acid HA and/or its sodium salt NaA. (Na+ions and solvent water molecules have been omitted for clarity.)
Notes
 Key concept problem 16.6
Keywords
 buffers
16-05-02UN
Title
 Serine
Caption
 Ball-and-stick model of serine, an amino acid.
Notes
 Structure of serine, for Problem 16.12
Keywords
 serine
16-06
Title
 Strong acid-strong base titration
Caption
 Figure 16.6 A strong acid-strong base titration curve. (a) In this pH titration, 0.100 M NaOH is added slowly from a buret to an HCl solution of unknown concentration. The pH of the solution is measured with a pH meter and is recorded as a function of the volume of NaOH added. (b) The pH titration curve for titration of 40.0 mL of 0.100 M HCl with 0.100 M NaOH. The pH increases gradually in the regions before and after the equivalence point, but increases rapidly in the region near the equivalence point. The equivalence point comes after addition of 40.0 mL of 0.100 M NaOH. The pH at the equivalence point is 7.00.
Notes
 Strong acid-strong base titration
Keywords
 titration, equivalence point
16-06-01UN
Title
 Strong base-strong acid titration
Caption
 A strong base-strong acid titration curve. The curve shown is for titration of 40.0 mL of 0.100 M NaOH with 0.100 M HCl. The pH at the equivalence point is 7.00.
Notes
 Strong base-strong acid titration
Keywords
 titration, equivalence point
16-07
Title
 Weak acid-strong base titration
Caption
 Figure 16.7 (a) A weak acid-strong base titration curve compared with (b) a strong acid-strong base curve. The curves shown are for titration of (a) 40.0 mL of 0.100 M CH3CO2H with 0.100 M NaOH (blue curve) and (b) 40.0 mL of 0.100 M HCl with 0.100 M NaOH (red curve). The pH ranges in which the acid-base indicators phenolphthalein and methyl red change color are indicated. Note that phenolphthalein is an excellent indicator for the weak acid-strong base titration because the equivalence point (a) is at pH 8.72; methyl red is an unsatisfactory indicator because it changes color well before the equivalence point. Either phenolphthalein or methyl red can be used for the strong acid-strong base titration because the curve rises very steeply in the region of the equivalence point (b) at pH 7.00.
Notes
 Weak acid-strong base titration curve compared to strong acid-strong base titration curve
Keywords
 titration curve, equivalence point, indicator
16-08
Title
 Various weak acid-strong base titrations
Caption
 Figure 16.8 Various weak acid-strong base pH titration curves. The curves shown are for titration of 40.0 mL of 0.100 M solutions of various weak acids with 0.100 M NaOH. In each case, the equivalence point comes after addition of 40.0 mL of 0.100 M NaOH, but the increase in pH at the equivalence point gets smaller and the equivalence point gets more difficult to detect as the Ka value of the weak acid decreases.
Notes
 Various weak acid-strong base titrations
Keywords
 titration, dissociation constant, equivalence point
16-08-01UN
Title
 Key Concept Problem 16.15
Caption
 The following pictures represent solutions at various points in the titration of a weak acid HA with aqueous NaOH. (Na+ions and solvent water molecules have been omitted for clarity.)
Notes
 Key concept problem 16.15
Keywords
 titration, equivalence point
16-09
Title
 Weak base-strong acid titration
Caption
 Figure 16.9 A weak base-strong acid titration curve. The curve shown is for titration of 40.0 mL of 0.100 M NH3 with 0.100 M HCl. The pH is 11.12 at the start of the titration, 9.25 (the pKa value for NH4+) in the buffer region halfway to the equivalence point, and 5.28 at the equivalence point. Note that methyl red is a good indicator for this titration, but phenolphthalein is unacceptable.
Notes
 Weak base-strong acid titration
Keywords
 titration, equivalence point, indicator
16-09-02UN
Title
 Alanine
Caption
 Ball-and-stick model of alanine, an amino acid.
Notes
 Structure of alanine, neutral form
Keywords
 alanine
16-10
Title
 Titration of a polyprotic acid
Caption
 Figure 16.10 Change in the pH of 1.00 L of a 1.00 M solution of H2A+on addition of solid NaOH. The protonated form of alanine, H2A+, is a diprotic acid, so the titration curve exhibits two equivalence points, at pH 6.02 and pH 11.85, and two buffer regions, near pH 2.34 and pH 9.69.
Notes
 Titration curve for a polyprotic acid
Keywords
 titration, polyprotic acid, equivalence point, isoelectric point
16-10-02UN
Title
 Methionine (cation)
Caption
 Ball-and-stick model of the protonated form of methionine, an amino acid.
Notes
 Structure of protonated methionine for Worked Example 16.6
Keywords
 methionine
16-10-04UN
Title
 Valine (cation)
Caption
 Ball-and-stick model of the protonated form of valine, an amino acid.
Notes
 Structure of protonated valine for Problem 16.19
Keywords
 valine
16-10-06UN
Title
 Saturated solution of CaF2
Caption
 A saturated solution of calcium fluoride in contact with solid CaF2 contains constant equilibrium concentrations of Ca2+(aq) and F-(aq) because at equilibrium the ions crystallize at the same rate as the solid dissolves.
Notes
 Equilibrium between the solid salt and the solvated ions in saturated solutions
Keywords
 saturation, solubility
16-10-09UN
Title
 Key Concept Problem 16.24
Caption
 The following pictures represent saturated solutions of three silver salts: AgX, AgY, and AgZ. (Other ions and solvent water molecules have been omitted for clarity.)
Notes
 Key concept problem 16.24
Keywords
 solubility
16-11
Title
 Common-ion effect and solubility
Caption
 Figure 16.11 The common-ion effect. The solubility of MgF2 at 25°C decreases markedly on addition of F-ions. Note that the calculated solubility is plotted on a logarithmic scale.
Notes
 Common-ion effect and solubility
Keywords
 common-ion effect, solubility
16-12
Title
 Effect of pH on solubility
Caption
 Figure 16.12 The solubility of CaCO3 at 25°C increases as the solution becomes more acidic because the CO32-ions combine with protons, thus driving the solubility equilibrium to the right. Note that the solubility is plotted on a logarithmic scale.
Notes
 Effect of pH on solubility
Keywords
 pH, solubility
16-13
Title
 Formation of complex ions
Caption
 Silver chloride is insoluble in water (left) but dissolves on addition of an excess of aqueous ammonia (right).
Notes
 The formation of complex ions causes the equilibrium to shift to the right, resulting in greater solubility of the initially insoluble salt.
Keywords
 complex ions, solubility
16-14
Title
 Solubililtyof AgCl in aqueous ammonia
Caption
 Figure 16.14 The solubility of AgCl in aqueous ammonia at 25°C increases with increasing ammonia concentration owing to formation of the complex ion Ag(NH3)2+. Note that the solubility is plotted on a logarithmic scale.
Notes
 Solubility of AgCl as a function of aqueous ammonia concentration
Keywords
 complex ions, solubility, concentration
16-16
Title
 Solubility of amphoteric hydroxides
Caption
 Figure 16.16 A plot of solubility versus pH shows that Al(OH)3 is an amphoteric hydroxide. Al(OH)3 is essentially insoluble between pH 4 and 10, but it dissolves both in strongly acidic and in strongly basic solutions.
Notes
 Amphoteric hydroxides exhibit increased solubility in strongly acidic and strongly basic solutions.
Keywords
 amphoteric hydroxides, solubility, pH
16-16-01UN
Title
 Solubility product and precipitation
Caption
 When 0.150 L of 0.10 M Pb(NO3)2 and 0.100 L of 0.20 M NaCl are mixed, a white precipitate of PbCl2 forms because the ion product is greater than Ksp.
Notes
 Predicting if a precipitate will be observed based on comparison of ion-product and solubility-product constant.
Keywords
 ion-product, solubility-product, precipitation
16-17
Title
 Qualitative analysis
Caption
 Figure 16.17 Flowchart for separation of metal cations in qualitative analysis.
Notes
 Qualitative analysis scheme for separation and identification of metal cations
Keywords
 qualitative analysis
16-18-02UN
Title
 Muscle tissue
Caption
 Muscle tissue is made of protein filaments.
Notes
 Muscle tissue and protein: intro into protein analysis by electrophoresis
Keywords
 protein, muscle
16-18-03UN
Title
 Acid-base chemistry of proteins
Caption
 Muscle tissue is made of protein filaments.
Notes
 Proteins have various acidic and basic sites spread throughout their structure. Changing pH can have a dramatic effect on the charge structure of the protein.
Keywords
 protein, pH, charge
16-19
Title
 Electrophoresis
Caption
 Muscle tissue is made of protein filaments.
Notes
 Depending on the pH of the mixture, proteins can be separated on the basis of charge using electrophoresis.
Keywords
 electrophoresis, protein, pH
16-20
Title
 Using electrophoresis
Caption
 Figure 16.20 (a) A normal electrophoresis pattern of blood serum. (b) An abnormal pattern, with elevated g-globulin, indicating the possibility of liver disease, collagen disorder, or infection.
Notes
 Examples of electrophoresis experiments for Problem 16.32
Keywords
 electrophoresis
16-20-001UN
Title
 Key Concept Summary
Caption
 Applications of Aqueous Equilibria key concept summary.
Notes
 Key concept summary Chapter 16
Keywords
 key concept, summary
16-20-01UN
Title
 Key Concept Problem 16.34
Caption
 The following pictures represent solutions that contain one or more of the compounds H2A, NaHA, and Na2A, where H2A is a weak diprotic acid.
Notes
 Key Concept Problem 16.34
Keywords
 key concept, buffers
16-20-02UN
Title
 Key Concept Problem 16.35
Caption
 The following pictures represent solutions that contain a weak acid HA (pKa = 6.0) and its sodium salt NaA. (Na+ions and solvent water molecules have been omitted for clarity.)
Notes
 Key Concept Problem 16.35
Keywords
 key concept, common-ion effect, pH
16-20-03UN
Title
 Key Concept Problem 16.36
Caption
 The strong acid HA is mixed with an equal molar amount of aqueous NaOH. Which of the pictures represents the equilibrium state of the solution?
Notes
 Key Concept Problem 16.36
Keywords
 key concept, titration
16-20-04UN
Title
 Key Concept Problem 16.37
Caption
 The following pictures represent solutions at various stages in the titration of a weak diprotic acid H2A with aqueous NaOH.
Notes
 Key Concept Problem 16.37
Keywords
 key concept, titration, equivalence point
16-20-05UN
Title
 Key Concept Problem 16.38
Caption
 The following pictures represent solutions at various stages in the titration of a weak base B with aqueous HCl.
Notes
 Key Concept Problem 16.38
Keywords
 key concept, titration, equivalence point
16-20-06UN
Title
 Key Concept Problem 16.39
Caption
 The following pictures represent solutions of AgCl, which also may contain ions other than Ag+and Cl-that are not shown. If solution (1) is a saturated solution of AgCl, classify solutions (2)-(4) as unsaturated, saturated, or supersaturated.
Notes
Keywords
16-20-07UN
Title
 Key Concept Problem 16.40
Caption
 The following pictures represent solutions of Ag2CrO4, which also may contain ions other than Ag+and CrO42-that are not shown. Solution (1) is in equilibrium with solid Ag2CrO4. Will a precipitate of solid Ag2CrO4 form in solutions (2)-(4)? Explain.
Notes
 Key Concept Problem 16.40
Keywords
 key concept, solubility, ion-product
16-20-08UN
Title
 Key Concept Problem 16.41
Caption
 The following plot shows two titration curves, each representing the titration of 50.0 mL of 0.100 M acid with 0.100 M NaOH.
Notes
 Key Concept Problem 16.41
Keywords
 key concept, titration, equivalence point, pKa
16-TB00.01UN
Title
 Principal reaction:
Caption
 Principal reaction:
Notes
Keywords
16-TB00.02UN
Title
 Principal reaction:
Caption
 Principal reaction:
Notes
Keywords
16-TB00.03UN
Title
 Principal reaction:
Caption
 Principal reaction:
Notes
Keywords
16-TB00.04UN
Title
 Principal reaction:
Caption
 Principal reaction:
Notes
Keywords
16-TB00.05UN
Title
 Neutralization reaction:
Caption
 Neutralization reaction:
Notes
Keywords
16-TB01
Title
 Table 16.1 Sample Results for pH Calculations at Various Points in the Titration of 40.0 mL of 0.100 M HCl with 0.100 M NaOH
Caption
Notes
Keywords
16-TB02
Title
 Table 16.2 Values for Some Ionic Compounds at 25°C
Caption
Notes
Keywords
16-TB02.01UN
Title
 Solubility equilibrium:
Caption
 Solubility equilibrium:
Notes
Keywords
16-TB02.02UN
Title
Caption
Notes
Keywords
16-TB03
Title
 Table 16.3 Solubility Products in Acid at 25°C for Metal Sulfides
Caption
Notes
Keywords
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