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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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