Answer: List the following compounds in order from

a. List the following alcohols in order from strongest acid to weakest acid: CCl3CH2OH Ka = 5.75 1013 Ka = 1.29 1013 Ka = 4.90 1013 CH2ClCH2OH CHCl2CH2OH b. Explain the relative acidities.

Which is a stronger base? a. \(\mathrm{HS}^{-} \text {or } \mathrm{HO}^{-}\) c. \(\mathrm{CH}_{3} \mathrm{OH}\ \\\text{or }\ \mathrm{CH}_{3} \mathrm{O}^{-}\) e. \(\mathrm{CH}_{3} \mathrm{COO}^{-} \text {or } \mathrm{CF}_{3} \mathrm{COO}^{-}\) b. \(\mathrm{CH}_{3} \mathrm{O}^{-} \text {or } \mathrm{CH}_{3} \overline{\mathrm{N}}H\) d. \(\mathrm{Cl}^{-}\ \text {or }\ \mathrm{Br}^{-}\) f. \(\mathrm{CH}_{3} \mathrm{CHClCOO}^{-}\ \text {or }\ \mathrm{CH}_{3} \mathrm{CHBrCOO}^{-}\)

Draw curved arrows to show where the electrons start from and where they end up in the following reactions:

a. List the following carboxylic acids in order from strongest acid to weakest acid: CH3CH2CH2COOH Ka = 1.52 105 CH3CH2CHCOOH Ka = 1.39 103 Cl ClCH2CH2CH2COOH Ka = 2.96 105 CH3CHCH2COOH Ka = 8.9 105 Cl b. How does the presence of an electronegative substituent such as Cl affect the acidity of a carboxylic acid? c. How does the location of the substituent affect the acidity of the carboxylic acid?

Draw the products of the following reactions:

For the following compound, a. draw its conjugate acid. b. draw its conjugate base. HOCH2CH2CH2NH2

List the following compounds in order from strongest acid to weakest acid:

For each of the following compounds, draw the form in which it will predominate at pH = 3, pH = 6, pH = 10, and pH = 14:

Give the products of the following acidbase reactions, and indicate whether reactants or products are favored at equilibrium (use the p Ka values that are given in Section 2.3 ):

a. List the following alcohols in order from strongest acid to weakest acid. b. Explain the relative acidities. CH2 CHCH2OH CH3CH2CH2OH HC CCH2OH

For each compound, indicate the atom that is most apt to be protonated.

a. Given the Ka values, estimate the p Ka value of each of the following acids without using a calculator (that is, is it between 3 and 4, between 9 and 10, and so on?): 1. nitrous acid (HNO 2 ), Ka = 4.0 * 10-4 3. bicarbonate 1HCO3 - 2 , Ka = 6.3 * 10-11 2. nitric acid (HNO 3 ), Ka = 22 4. hydrogen cyanide (HCN), Ka = 7.9 * 10-10 5. formic acid (HCOOH), Ka = 2.0 * 10-4 b. Determine the exact p Ka values, using a calculator. c. Which is the strongest acid?

A single bond between two carbons with different hybridizations has a small dipole. What is the direction of the dipole in the indicated bonds? a. CH3 CH CH2 b. CH3 C CH

T enormin, a member of the group of drugs known as beta-blockers, is used to treat high blood pressure and improve survival after a heart attack. It works by slowing down the heart in order to reduce its workload. Which hydrogen in Tenormin is the most acidic?

From which acids can HO - remove a proton in a reaction that favors product formation?

a. For each of the following pairs of reactions, indicate which one has the more favorable equilibrium constant (that is, which one most favors products): 1. CH3CH2OH + NH3 L CH3CH2O - + N + H4 2. CH3CH2OH + NH3 L CH3CH2O - + N + H4 or or CH3OH + NH3 L CH3O - + N + H4 CH3CH2OH + CH3NH2 L CH3CH2O - + CH3N + H3 b. Which of the four reactions has the most favorable equilibrium constant?

You are planning to carry out a reaction that produces protons. The reaction will be buffered at pH = 10.5. Would it be better to use a protonated methylamine/methylamine buffer or a protonated ethylamine/ethylamine buffer? (p Ka of protonated methylamine = 10.7; p Ka of protonated ethylamine = 11.0)

Which is a stronger acid?

Citrus fruits are rich in citric acid, a compound with three COOH groups. Explain the following: a. The i rst p Ka (for the COOH group in the center of the molecule) is lower than the p Ka of acetic acid. b. The third p Ka is greater than the p Ka of acetic acid.

Given that pH + pOH = 14 and that the concentration of water in a solution of water is 55.5 M, show that the p Ka of water is 15.7. (Hint: pOH = -log 3HO- 4

How could you separate a mixture of the following compounds? The reagents available to you are water, ether, 1.0 M HCl, and 1.0 M NaOH. ( Hint: See Problem 42 .)

Carbonic acid has a p Ka of 6.1 at physiological temperature. Is the carbonic acid/bicarbonate buffer system that maintains the pH of the blood at 7.4 better at neutralizing excess acid or excess base?

a. If an acid with a p Ka of 5.3 is in an aqueous solution of pH 5.7, what percentage of the acid is present in its acidic form? b. At what pH will 80% of the acid exist in its acidic form?

Calculate the pH values of the following solutions . ( Hint: See Special Topic I in the Study Guide and Solutions Manual .) a. a 1.0 M solution of acetic acid ( pKa = 4.76 ) b. a 0.1 M solution of protonated methylamine ( pKa = 10.7 ) c. a solution containing 0.3 M HCOOH and 0.1 M HCOO- (p Ka of HCOOH = 3.76 )

Problem 1P Which of the following are not acids? CH3COOH CO2 HNO2 HCOOH CCl4

Estimate the \(pK_a\) values of the following compounds: a. \(CH_3CH_2CH_2NH_2\) b. \(CH_3CH_2CH_2OH\) c. \(CH_3CH_2COOH\) d. \(CH_3CH_2CH_2NH_3\)

a. Which is a stronger base, \(\mathrm{CH}_3\mathrm{COO}^-\ \text{or }\ \mathrm{HCOO}^-\)? (The \(\mathrm{p} K_{a}\) of \(\mathrm{CH}_{3} \mathrm{COOH}\) is 4.8; the \(\mathrm{p} K_{a}\) of HCOOH is 3.8.) b. Which is a stronger base, \(\mathrm{HO}^-\ \text{or }\ ^-\mathrm{NH}_2\)? (The \(\mathrm{p} K_{a}\) of \(\mathrm{H}_{2} \mathrm{O}\) is 15.7; the \(\mathrm{p} K_{a}\) of \(\mathrm{NH}_{3}\) is 36.) c. Which is a stronger base, \(\mathrm{H}_{2} \mathrm{O} \text { or } \mathrm{CH}_{3} \mathrm{OH}\)? (The \(\mathrm{p} K_{a}\) \(\mathrm{H}_{3} \mathrm{O}^{+}\) is -1.7; the \(\mathrm{p} K_{a}\) of \(\mathrm{CH}_{3} \mathrm{OH}_{2}\) is -2.5.)

Using the \(p K_{a}\) values in Section \(2.3\) , rank the following species in order from strongest base to weakest base: Equation Transcription: Text Transcription: pK_a 2.3

Problem 23P List the halide ions ( F-, Cl-, Br-, and I-) in order from strongest base to weakest base.

Problem 24P a. Which is more electronegative, oxygen or sulfur? b. Which is a stronger acid, H2O or H2S? c. Which is a stronger acid, CH3OH or CH3SH?

Which is a stronger acid?

For each of the following compounds (shown in their acidic forms) write the form that will predominate in a solution at \(p H=5.5\) : Equation Transcription: Text Transcription: pH=5.5

Problem 37P As long as the pH is not less than _________, at least 50% of a protonated amine with a pKa value of 10.4 will be in its neutral, nonprotonated form.

a. Indicate whether a carboxylic acid \((\mathrm{RCOOH})\) with a \(p K_{a}\) value of \(4.5\) will have more charged molecules or more neutral molecules in a solution with the following \(p H\): 1. \(p H=1\) 3. \(p H=5\) 5. \(p H=10\) 2. \(p H=3\) 4. \(p H=7\) 6. \(p H=13\) b. Answer the same question for a protonated amine with a \(p K_{a}\) value of \(9\). c. Answer the same question for an alcohol \((R O H)\) with a \(p K_{a}\) value of \(15\). Equation Transcription: Text Transcription: (RCOOH) pK_a 4.5 pH pH=1 pH=3 pH=5 pH=7 pH=10 pH=13 9 (ROH) 15

Draw curved arrows to show where the electrons start from and where they end up in the following reactions:

a. List the following carboxylic acids in order from strongest acid to weakest acid: b. How does the presence of an electronegative substituent such as \(\mathrm{Cl}\) affect the acidity of a carboxylic acid? c. How does the location of the substituent affect the acidity of the carboxylic acid? Equation Transcription: Text Transcription: Cl

Draw the products of the following reactions:

From which acids can \(\mathrm{HO}^{-}\) remove a proton in a reaction that favors product formation? Equation Transcription: Text Transcription: HO^-

a. For each of the following pairs of reactions, indicate which one has the more favorable equilibrium constant (that is, which one most favors products): b. Which of the four reactions has the most favorable equilibrium constant?

Problem 63P You are planning to carry out a reaction that produces protons. The reaction will be buffered at pH = 10.5. Would it be better to use a protonated methylamine/methylamine buffer or a protonated ethylamine/ethylamine buffer? (pKa of protonated methylamine = 10.7; pKa of protonated ethylamine = 11.0)

Problem 5P An acid has a Ka of 4.53 x 10-6 in water. What is its Keq for reaction with water in a dilute solution? ([H2O] = 55.5 M)

Problem 6P Butyric acid, the compound responsible for the unpleasant odor and taste of sour milk, has a pK.a value of 4.82. What is its Ka value? Is it a stronger or a weaker acid than vitamin C?

Problem 7P Antacids are compounds that neutralize stomach acid. Write the equations that show how Milk of Magnesia, Alka-Seltzer, and Turns remove excess acid. a. Milk of Magnesia: Mg(OH)2 b. Alka-Seltzer: KHCO3 and NaHCO3 c. Turns: CaCO3

Which of the following bases can remove a proton from acetic acid in a reaction that favors products? \(\mathrm{HO}^{-} \quad \mathrm{CH}_{3} \mathrm{NH}_{2} \quad \mathrm{HC} \equiv \mathrm{C}^{-} \quad \mathrm{CH}_{3} \mathrm{OH} \quad \mathrm{H}_{2} \mathrm{O} \quad \mathrm{Cl}^{-}\) Equation Transcription: ? Text Transcription: HO^- CH_3 NH_2 HC trigram C^- CH_3 OH H_2 O Cl^-

Calculate the equilibrium constant for the acid–base reaction between the reactants in each of the following pairs: a. \(\mathrm{HCI}+\mathrm{H}_{2} \mathrm{O}\) b. \(\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{H}_{2} \mathrm{O}\) c. \(\mathrm{CH}_{3} \mathrm{NH}_{2}+\mathrm{H}_{2} \mathrm{O}\) d. \(\mathrm{CH}_{3} \mathrm{~N}^{+} \mathrm{H}_{3}+\mathrm{H}_{2} \mathrm{O}\) Equation Transcription: Text Transcription: HCI + H_2 O CH_3 COOH + H_2 O CH_3 NH_2 + H_2 O CH_3 N^+ H_3 + H_2 O

Problem 19P List the ions (-CH3, -NH2, HO-, and F-) in order from most basic to least basic.

List the following compounds in order from strongest acid to weakest acid:

Which is a stronger base?

Fosamax has six acidic groups. The structure of the active form of the drug is shown in the box. (Notice that the phosphorus atom in Fosamax and the sulfur atom in Problem \(33\) can be surrounded by more than eight electrons since \(P \text { and } S\) are below the second row of the periodic table.) a. The \(\mathrm{OH}\) groups bonded to phosphorus are the strongest acids of the six groups. Why? b. Which of the remaining four groups is the weakest acid? Equation Transcription: Text Transcription: 33 P and S OH

Given that \(\mathrm{C}_{6} \mathrm{H}_{11} \mathrm{COOH}\) has a \(p K_{a}=4.8\) and \(C_{6} H_{11} N^{+} H_{3}\) has a \(p K_{a}=10.7\), answer the following: a. What pH would you make the water layer in order to cause both compounds to dissolve in it? b. What pH would you make the water layer in order to cause the acid to dissolve in the water layer and the amine to dissolve in the ether layer? c. What pH would you make the water layer in order to cause the acid to dissolve in the ether layer and the amine to dissolve in the water layer? Equation Transcription: Text Transcription: C_6 H_11 COOH pK_a =4.8 C_6 H_11 N^+ H_3 pK_a =10.7

Problem 43P Write the equation that shows how a buffer made by dissolving CH3COOH and CH3COO?Na+ in water prevents the pH of a solution from changing when a. a small amount of H+ is added to the solution. b. a small amount of HO? is added to the solution.

Draw the products of the following reactions. Use curved arrows to show where the pair of electrons starts from and where it ends up.

Give the products of the following acid–base reactions, and indicate whether reactants or products are favored at equilibrium (use the \(p K_{a}\) values that are given in Section \(2.3\) ): Equation Transcription: Text Transcription: pK_a 2.3

a. List the following alcohols in order from strongest acid to weakest acid. b. Explain the relative acidities. \(\mathrm{CH}_{2}=\mathrm{CHCH}_{2} \mathrm{OH}\) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) \(\mathrm{HC} \equiv \mathrm{CCH}_{2} \mathrm{OH}\) Equation Transcription: ? Text Transcription: CH_2 = CHCH_2 OH CH_3 CH_2 CH_2 OH HC trigram CCH_2 OH

For each compound, indicate the atom that is most apt to be protonated.

How could you separate a mixture of the following compounds? The reagents available to you are water, ether, \(1.0\ \mathrm{M\ HCI}\), and \(1.0\ \mathrm{M\ NaOH}\). ( Hint: See Problem \(42\) .) Equation Transcription: Text Transcription: 1.0 M HCI 1.0 M NaOH 42

Problem 68P Carbonic acid has a pKa of 6.1 at physiological temperature. Is the carbonic acid/bicarbonate buffer system that maintains the pH of the blood at 7.3 better at neutralizing excess acid or excess base?

Problem 69P a. If an acid with a pKa of 5.3 is in an aqueous solution of pH 5.7, what percentage of the acid is present in its acidic form? b. At what pH will 80% of the acid exist in its acidic form?

Problem 8P Are the following body fluids acidic or basic? a. bile (pH = 8.4) b. urine (pH = 5.9) c. spinal fluid (pH - 7.4)

Draw the conjugate acid of each of the following:

a. Write an equation showing \(\mathrm{CH}_{3} \mathrm{OH}\) reacting as an acid with \(\mathrm{NH}_{3}\) and an equation showing it reacting as a base with HCl. b. Write an equation showing \(\mathrm{NH}_{3}\) reacting as an acid with \(\mathrm{CH}_{3} \mathrm{O}^{-}\) and an equation showing it reacting as a base with HBr.

List the carbanions shown in the margin in order from most basic to least basic.

Which is a stronger acid?

a. Draw the products of the following reactions: A \(\mathrm{HC} \equiv \mathrm{CH}+\mathrm{CH}_{3} \overline{\mathrm{C}} \mathrm{H}_{2} \rightleftharpoons\) B \(H_{2} \mathrm{C}=\mathrm{CH}_{2}+H C \equiv \mathrm{C}^{-} \rightleftharpoons\) C \(\mathrm{CH}_{3} \mathrm{CH}_{3}+\mathrm{H}_{2} \mathrm{C}=\overline{\mathrm{C}} \mathrm{H} \rightleftharpoons\) b. Which of the reactions favor formation of the products? Equation Transcription: ?? ?? ? Text Transcription: HC trigram CH+CH_3 overline C H_2 right left harpoons H_2 C=CH_2 + HC trigram C^- right left harpoons CH_3 CH_3 + H_2 C = overline C H right left harpoons

Which is a stronger acid? Why?

Draw resonance contributors for the following species:

Problem 35P Using the table of pKa values given in Appendix I, answer the following: a. Which is the most acidic organic compound in the table? b. Which is the least acidic organic compound in the table? c. Which is the most acidic carboxylic acid in the table? d. Which is more electronegative, an sp3 oxygen or an sp2 oxygen? (Hint: Pick a compound in Appendix I with a hydrogen attached to an sp2 oxygen and one with a hydrogen attached to an sp3 oxygen, and compare their pKa values.) e. Which compounds demonstrate that the relative electronegativities of a hybridized nitrogen atom are sp > sp2 > sp3?

What products are formed when each of the following reacts with \(\mathrm{HO}^{-}\)? Equation Transcription: Text Transcription: HO^-

a. List the following alcohols in order from strongest acid to weakest acid: \(\mathrm{CCl}_{3} \mathrm{CH}_{2} \mathrm{OH}\) \(\mathrm{CH}_{2} \mathrm{ClCH}_{2} \mathrm{OH}\) \(\mathrm{CHCl}_{2} \mathrm{CH}_{2} \mathrm{OH}\) \(K_{a}=5.75 \times 10^{-13}\) \(K_{a}=1.29 \times 10^{-13}\) \(K_{a}=4.90 \times 10^{-13}\) b. Explain the relative acidities. Equation Transcription: Text Transcription: CCl_3 CH_2 OH K_a = 5.75 times 10^-13 CH_2 ClCH_2 OH K_a =1.29 times 10^-13 CHCl_2 CH_2 OH K_a = 4.90 times 10^-13

Which is a stronger base? a. \(H S^{-} \text {or } H O^{-}\) c. \(\mathrm{CH}_{3} \mathrm{OH} \text { or } \mathrm{CH}_{3} \mathrm{O}^{-}\) e. \(\mathrm{CH}_{3} \mathrm{COO}^{-} \text {or } \mathrm{CF}_{3} \mathrm{COO}^{-}\) b. \(\mathrm{CH}_{3} \mathrm{O}^{-} \text {or } \mathrm{CH}_{3} \overline{\mathrm{N}} H\) d. \(\mathrm{Cl}^{-} \text {or } \mathrm{Br}^{-}\) f. \(\mathrm{CH}_{3} \mathrm{CHClCOO}^{-} \text {or } \mathrm{CH}_{3} \mathrm{CHBrCOO}^{-}\) Equation Transcription: Text Transcription: HS^- or HO^- CH_3 O^- or CH_3 overline N H CH_3 OH or CH_3 O^- Cl^- or Br^- CH_3 COO^- or CF_3 COO^- CH_3 CHClCOO^- or CH_3 CHBrCOO^-

a. Given the \(K_{a}\) values, estimate the \(p K_{a}\) value of each of the following acids without using a calculator (that is, is it between 3 and4, between 9 and 10, and so on?): 1. nitrous acid \(\left(H N O_{2}\right), K_{a}=4.0 \times 10^{-4}\) 3. bicarbonate \(\left(\mathrm{HCO} 3^{-}\right), K_{a}=6.3 \times 10^{-11}\) 2. nitric acid \(\left(H N O_{3}\right), K_{a}=22\) 4. hydrogen cyanide \((H C N), K_{a}=7.9 \times 10^{-10}\) 5. formic acid \((H C O O H), K_{a}=2.0 \times 10^{-4}\) b. Determine the exact \(p K_{a}\) values, using a calculator. c. Which is the strongest acid? Equation Transcription: Text Transcription: K_a pK_a (HNO_2 ), K_a =4.0 times 10^-4 (HNO_3 ), K_a =22 (HCO3^-), K_a =6.3 times 10^-11 (HCN), K_a =7.9 times 10^-10 (HCOOH), K_a =2.0 times 10^-4

A single bond between two carbons with different hybridizations has a small dipole. What is the direction of the dipole in the indicated bonds?

Tenormin, a member of the group of drugs known as beta-blockers, is used to treat high blood pressure and improve survival after a heart attack. It works by slowing down the heart in order to reduce its workload. Which hydrogen in Tenormin is the most acidic?

Problem 70P Calculate the pH values of the following solutions. (Hint : See Special Topic I in the Study Guide and Solutions Manual.) a. a 1.0 M solution of acetic acid (pKa = 4.76) b. a 0.1 M solution of protonated methylamine (pKa = 10.7) c. a solution containing 0.3 M HCOOH and 0.1 M HCOO- (pKa of HCOOH = 3.76)

Draw the products of the acid–base reaction when a. HCl is the acid and \(NH_3\) is the base. b. \(H_2 O\) is the acid and \(^{-}NH_2\) is the base.

Problem 3P a. Draw the conjugate acid of each of the following: 1. NH3 2. Cl? 3. HO? 4. H20 ________________ b. Draw the conjugate base of each of the following: 1. NH3 2. HBr 3. HNQ3 4. H20

Problem 4P a. Which is a stronger acid, one with a pKa of 5.2 or one with a pKa of 5.8? ________________ b. Which is a stronger acid, one with an acid dissociation constant of 3.4 X10?3 with an acid dissociation constant of 2.1 X1CT4 ?

Does methanol behave as an acid or a base when it reacts with methylamine?

a. For each of the acid–base reactions in Section \(2.3\) , compare the \(p K_{a}\) values of the acids on either side of the equilibrium arrows to prove that the equilibrium lies in the direction indicated. (The \(p K_{a}\) values you need can be found in Section \(2.3\) or in Problem \(12\) .) b. Do the same for the acid–base reactions in Section \(2.1\) . Equation Transcription: Text Transcription: 2.3 pK_a 12 2.1

Problem 16P Ethyne has a pKa value of 25, water has a pKa value of 15.7, and ammonia (NH3) has a pKa value of 36. Draw the equation, showing equilibrium arrows that indicate whether reactants or products are favored, for the acid–base reaction of ethyne with a. HO-. b. –NH2. c. Which would be a better base to use if you wanted to remove a proton from ethyne, HO- or -NH2 ?

Problem 26P Which of the halide ions (F? , Cl? , Br? , I?) is the strongest base? Which is the weakest base?

Which is a stronger base? a. \(\mathrm{H}_{2} \mathrm{O} \text { or } \mathrm{HO}^{-}\) b. \(\mathrm{H}_{2} \mathrm{O} \text { or } \mathrm{NH}_{3}\) d. \(\mathrm{CH}_{3} \mathrm{O}^{-} \text {or } \mathrm{CH}_{3} \mathrm{~S}^{-}\) Equation Transcription: Text Transcription: H_2 O or HO^- H_2 O or NH_3 CH_3 O^- or CH_3 S^-

Which is a stronger acid? a. \(\mathrm{CH}_{3} \mathrm{OCH}_{2} \mathrm{CH}_{2} \mathrm{OH} \text { or } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) b. \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{~N}^{+} \mathrm{H}_{3} \text { or } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{O}^{+} \mathrm{H}_{2}\) c. \(\mathrm{CH}_{3} \mathrm{OCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH} \text { or } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OCH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) Equation Transcription: Text Transcription: CH_3 OCH_2 CH_2 OH or CH_3 CH_2 CH_2 CH_2 OH CH_3 CH_2 CH_2 over+N H_3 or CH_3 CH_2 CH_2 over+O H_2 CH_3 OCH_2 CH_2 CH_2 OH or CH_3 CH_2 OCH_2 CH_2 OH

A naturally occurring amino acid such as alanine has a group that is a carboxylic acid and a group that is a protonated amine. The \(p K_{a}\) values of the two groups are shown. a. If the \(p K_{a}\) value of carboxylic acid such as acetic acid is about 5 (see Table \(2.1\) ), then why is the \(p K_{a}\) value of the carboxylic acid group of alanine so much lower? b. Draw the structure of alanine in a solution at \(p H=0\). c. Draw the structure of alanine in a solution at physiological \(p H\) (\(p H=7.4\)). d. Draw the structure of alanine in a solution at \(p H=12\). e. Is there a \(p H\) at which alanine will be uncharged (that is, neither group will have a charge)? f. At what \(p H\) will alanine have no net charge (that is, the amount of negative charge will be the same as the amount of positive charge)? Equation Transcription: Text Transcription: pK_a 2.1 pH=0 pH 7.4 pH=12 pH

Problem 40P a. At what pH will the concentration of a compound with a pKa = 8.4 be 100 times greater in its basic form than in its acidic form? b. At what pH will the concentration of a compound with a pKa = 3.7 be 10 times greater in its acidic form than in its basic form? c. At what pH will the concentration of a compound with a pKa = 8.4 be 100 times greater in its acidic form than in its basic form? d. At what pH will 50% of a compound with a pKa = 7.3 be in its basic form? e. At what pH will the concentration of a compound with a pKa = 4.6 be 10 times greater in its basic form than in its acidic form?

For each of the following compounds, indicate the \(p H\) at which a. \(50 \%\) of the compound will be in a form that possesses a charge. b. more than \(99 \%\) of the compound will be in a form that possesses a charge. Equation Transcription: Text Transcription: pH 50% 99%

Problem 52P For the following compound, a. draw its conjugate acid. b. draw its conjugate base. HOCH2CH2CH2NH2

List the following compounds in order from strongest acid to weakest acid \(\begin{array}{llll}\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH} & \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{NH}_{2} & \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{SH} & \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{3}\end{array}\)

For each of the following compounds, draw the form in which it will predominate at \(p H=3, p H=6, p H=10, \text { and } p H=14\): Equation Transcription: Text Transcription: pH=3, pH=6, pH=10, and pH=14

Which is a stronger acid? a. \(\mathrm{CH}_{2}=\mathrm{CHCOOH} \text { or } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH}\) c. \(\mathrm{CH}_{2} \mathrm{CHCOOH} \text { or } \mathrm{HC} \equiv \mathrm{CCOOH}\) Equation Transcription: ? Text Transcription: CH_2 = CHCOOH or CH_3 CH_2 COOH CH_2 = CHCOOH or HC trigram CCOOH

Citrus fruits are rich in citric acid, a compound with three \(\mathrm{COOH}\) groups. Explain the following: a. The first \(p K_{a}\) (for the \(\mathrm{COOH}\) group in the center of the molecule) is lower than the pKa of acetic acid. b. The third \(p K_{a}\) is greater than the \(p K_{a}\) of acetic acid. Equation Transcription: Text Transcription: COOH pK_a

Problem 66P Given that pH + pOH = 14 and that the concentration of water in a solution of water is 55.5 M, show that the pKa of water is 15.7. (Hint: pOH = -log [HO-])