Answers to Selected Odd Numbered Problems

CHAPTER 1 Problems

(b) 299 kj/mol; junction of UV with visible region

(c) 160 kj/mol; junction of visible and infrared regions

(d) 29.9 kj/mol; beginning of thermal IR region

Box 1-1, Problem 1 [O*] = kt [02]/(k7 [M] +

Additional Problems

Overall: 3 02 + UV photon-» 2 03

NO + 03->N02 + 02

Overall: 2 03 + 2 photons-* 3 02

5. 491 nm; visible

2.5 X 10~12 g cm"3 y^1 9. 1.5 X 10~6

CHAPTER 2 Problems

2-5 CF30 + 03-»CF300 + 02

Green Chemistry Questions

3. No, not if the carbon dioxide is a waste by-product from another process. 5. Harpin is applied to the plant, which elicits the plant's own natural defenses.

Additional Problems 1. (b) 4 X 10l5g 3. (a) 140 (b) 10

7. Worse, since less Br is tied up in inactive forms.

CHAPTER 3

Problems

3-3 Increases the ozone concentration.

3-5 8 NH3 + 6 N02-»7 Nz + 12 H20

0.0092 g 3-7 1.2 X 10^7 M 3-9 0.59 ppm 3-11 156 kg

3-15 3:1 ratio; area is bigger with smaller particles.

(c) 1.3 X 10~9M Problem 3 (a) 9.3 X 1011 molecules/cm3

AN-1

Green Chemistry Questions

1. (a) Both are volatile and flammable hydrocarbons (VOCs); vapors would contribute to pollution of the troposphere; flammability would reduce worker safety.

(b) It is a VOC and would contribute to tropospheric pollution, but it is not flammable.

(c) It is a greenhouse gas, but waste carbon dioxide is used and recycled.

3. First pair: The cation has a delocalized charge and two nonpolar groups. Second pair: The charge on the anion is dispersed over the four chlorines, and the cation has a bulky nonpolar group. Third pair: Both the cation and anion have nonpolar bulky groups, and the charge on the anion is delocalized. Fourth pair: The charge on the anion is delocalized, and the cation has four nonpolar bulky groups.

Additional Problems

1. 4 X 1010 molecules cm-3 sec-1;

4 X 105 molecules cm-3 sec-1; that with 03 -»NO + N

rate = k [O] [N2] (b) Factor of 2.2 X 103 5. (a) 03 + 2KI + H20-(b) 120 ppb 7. 1.0% 9. 8 days

CHAPTER 4

Problems

4-1 NH4+ + 3 H20-*N03" + 10 H+ + 8e~

Additional Problems 1. 4.3 X 10~5 M; 0.68; western 3. 3.7 X 109 g

CHAPTER 5 Problems

5-1 CFCs have no H or multiple bonds, so they don't react with OH or light and thus don't oxidize. No, since CH2C12 has H atoms and so it will react with OH. 5-3 Quite endothermic. 5-5 If a C-bonded H is abstracted by OH, the C-centered radical H2COH will lose the hydroxyl H by 02 abstraction, producing formaldehyde. If instead OH abstracts the OH hydrogen initially, the resulting C-centered H3CO radical loses H to 02 abstraction, producing formaldehyde. 5-7 Overall: H2CO + 2 NO + 2 02 + sunlight

-»C02 + H20 + 2 N02

No increase in the number of free radicals.

5-9 Overall: CH3(H)CO + 7 02 + 7 NO-»

2 C02 + 7 N02 + 4 OH 5-11 Same as for Problem 5-7. 5-13 CH3OOH and 02 5-15 (a) 03, CIO, BrO, HOO

(b) 03, CIO, BrO, HOO, N02

(c) 03, CIO, BrO, HOO, N02

(e) When 2 03 or 2 HOO react. 5-17 (a) CIO + NOz-» C10N02

(c) Reaction of CIO with UV or O or NO; photolysis of ClOOCl.

5-19 Cycle destroys ozone if N02 reacts with O, but not if N02 decomposes in sunlight.

Additional Problems

1. CO + OH HOCO + 02 HOO + NO NO2 + UV O + O,

Overall: CO + 03 -> COz + 02

CHAPTER 6

Problems

6-3 CO arid NO; their stretching frequencies must lie outside the thermal 1R range. 6-5 0.440 tonne; 0.27 g 6-7 1 X 108 kg 6-9 485 Tg

Green Chemistry Questions

Additional Problems

1. (a) Symmetric and antisymmetric stretch and bending vibrations for both.

(b) Only the S02 symmetric stretch will contribute much,

(c) Short atmospheric lifetimes. 3. 0.48

7. Sharply increased air temperature. 9. 1180 L; 13,500 L; 23,500 L

CHAPTER 7

Problems

7-1 t = 0.69/k; 17.3, 23.1, 46.2, and 69.3 years; 115 years; 4.6%

7-3 0.00112, 0.00152, and 0.00254 mol C02/kJ

7-7 2.274 tonnes

Green Chemistry Questions i. (a) 2

3. Growing crops requires fertilizers and pesticides. Encr^' is needed to plant, cultivate, and harvest; to produce, transport, and apply fertilizers and pesticides; to make and run tractors; and to transport seeds, biomass, monomers, and polymers. Use of land to produce crops for chemicals also removes land that could be used to produce food and feed.

Additional Problems

For all kinds, 40%

CHAPTER 8

Problems

8-5 Slightly exothermic, small loss.

8-9 02 + 2 H20 + 4 e~-»4 OH"

2 OH" + H2-» 2 HzO + 2 e~

8-13 120 kj g-1; H2 is superior by weight, but methane is superior by volume.

Green Chemistry Questions

3. Transesterfication (addition-elimination)

5. The high vapor pressure of methanol may result in vapor lock, whereas the low vapor pressure of both ethylene glycol and glycerin may cause difficulty in starting at cold temperatures.

Additional Problems

1. 5.6 X 1024 J; 0.007% 3. One-third of the CO

3 C + 4 HzO ^ 2 CH3OH + COz 7. 0.0011 EJ

CHAPTER 9

Problems

9-3 49%; 65%; yes, substantially above

9-5 2H + 2He -> ¿He + }p (or }H)

2 2He -> 2He + 2 {p (or 2 }H)

Additional Problems

1. °e; 22Na j 2oNe + °e; 13N j '¿C + Je 3. The effusion rate of 235UF6 is 0.43% faster than that of238UF6. Since very little enrichment occurs in a single step, it is necessary to repeat the process hundreds of times to achieve suitable enrichment.

CHAPTER 10

Problems

10-1 (a) 4.0 X 10"5 ppm; 0.040 ppb

10-7 0.00010 mg/kg/day; 0.0055 mg/day Box 10-3, Problem 1 In air: 9.9 X 10"11 mol/m3 In water: 2.3 X 10 "11 mol/m3 In sediment: 5.7 X 10-7 mol/m3

Green Chemistry Questions

3. (a) A pesticide must meet one or more of the following requirements: (1) It reduces pesticide risks to human health.

(2) It reduces pesticide risks to nontarget organisms.

(3) It reduces the potential for contamination of valued environmental resources.

(4) It broadens adoption of IPM or makes it more effective.

Additional Problems

5. Yes, since concentration is 4.7 ppb.

CHAPTER 11

Problems

11-1 No, the same Yes

The unique ones are 1,2; 1,3; 1,4; 1,6; 1,7; 1,8; 1,9; 2,3; 2,7; 2,8. 11-3 (a) 2,3,5,6- and 2,3,4,5-tetrachlorophenols (b) Two 2,3,5,6-tetrachlorophenols produce the 1,2,4,6,7,9-PCDD. Two 2,3,4,5-tetrachlorophenols produce the 1,2,3,6,7,8-PCDD. 11-5 1.87 X 105 molecules 11-7 2,3; 2,4; 2,5; 2,6; 3,4; 3,5; 2,2'; 2,3'; 2,4'; 2,5'; 2,6'; 3,3'; 3,4'; 3,5'; 4,4' With rotation, 2,2' and 2,6' intercon-vert, as do 2,3' and 2,5', as well as 3,3' and 3,5'.

11-9 1,2; 1,3; 1,4; 2,3; 2,4; 3,4; 1,6; 1,7; 1,8; 1,9; 2,6; 2,7; 2,8; 3,6; 3,7; 4,6 dichlorodibenzofurans 11-11 28.6 pg

Box 11-1, Problem 1 2,6-dichlorophenol +

2,3,4-trichlorophenol, or 2,3-dichlorophenol + 2,3,6-trichlorophenol Box 11-2, Problem 1 1-chlorodibenzofuran, and 1,4-, 1-6-, and 1 -9-dichlorofurans

Green Chemistry Questions

Additional Problems

1. (a) One 2,3,4,5- and one 2,3,4,6-tetrachlorophenol

(b) One 2,3,4,6- and one 2,3,5,6-tetrachlorophenol

(c) One 2,3,4,6- and either 2,3,4,5- or 2,3,5,6-tetrachlorophenol

3. Dechlorination; dioxins more toxic than the originals may be produced. 5. 2,3-, 2,2'-, and 2,3'-dichlorobiphenyls; 2,3,2'-trichlorobiphenyl

7. 2,4,5,3'>2,4,3', 4'>2,4, 2', 6' 9. 2.0 X 10"12 mol/m3; 1.5 X 10~10 mol/m3; 4.9 X 10"5 mol/m3

CHAPTER 12

Problems

12-5 Less; larger

12-7 3.7 years; 45,000

CHAPTER 13

13-7 7.9 X 10"3 M; 6.3 X 10~20 M; 8.32; 2.51 13-9 15.2

13-11 (a) N03" + 2 H+ + 2 e~-»

(c) 14.9 - pH - 0.5 log ([N021/[N031)

13-13 8.3 X 10~"5 M; solubility increases with increasing temperature. 13-15 8.0 X 10"4 M 13-17 10.3

13-19 1.02 Xl0"3 M 13-21 30 mg CaC03/L

Green Chemistry Questions

1. It removes the outermost layer of the raw cotton fiber, know as the cuticle, which makes the fiber wettable for bleaching and dyeing. 3. (a) 2

Additional Problems

3. (a) S042" + 10 H+ + 8 e~->H2S + 4H,0

(b) PE = 5.75 - (5/4) pH - (1/8) log (Ph2s/[S042~])

(c) 10 136 atm, absolutely negligible 5. 9.17

CHAPTER 14 Problems

14-1 Ca(HC03)2 + Ca(OH)2->

1:1 ratio

14-5 11 ppm nitrogen; slightlv less stringent

2 H20 + 2 e_-» H2 + 2 OFT

Fe(s) + 2 H20-» Fe2+ + 2 OH" + I I:(g)

14-9 4 Fe + C2C14 + 4 H20-»

4 Fe2+ + C2H4 + 4 CI" + 4 OH^

14-11 5.5 X 10"5; 0.0055; 0.55; 55 14-13 N0,N02,N02",N03" 14-17 214,3 kj/mol; 558 nm; 45%

Box 14-3, Problem 1 t = [In (k1/k2)]/(lc1 - k2)

Green Chemistry Questions

1, It is biodegradable and its synthesis is performed under mild conditions; it uses only water as a solvent; and excess ammonia is recycled.

Additional Problems

5. An O—O bond, as in H0S0200^ ; , so it needs to eain an electron to become -2,____

CH3CC12 + Cl~ * CH,CC13 + H2O C03~ + OH~

C03z" + OH -Strong acid or a soluble calcium or magnesium salt; about 10 M. 11. 3.73, 0.019%; 4.23, 0.059%

CHAPTER 15

Problems

0.051 g

0.5 mg; 2.0 X 105 g 2 X 10~5g

Green Chemistry Questions

3. Lower air pollution, better corrosion protection, and reduced waste.

Additional Problems

1. Yes; yes, the answer changes. 3. H3As04 for pH < 2.20; H,As04~ from 2.20 to 6.89; HAs042" from 6.89 to 11.49;

As04 for pH> 11.49; 17; 0.17 H+ liberates metals from sulfides; liberated metals enter the food chain and affect human health.

13 mg m~3, must be greater than the threshold limit.

CHAPTER 16

Problems

16-1 3.9 L 16-3 C3H302 16-5 o

16-7 (a) 2 C12H6Cl4 + 25 O,->

(b) C12H6C14 + 23 H2-»

Green Chemistry Questions

1, It is biodegradable; as a result, it places less of a load on the environment. The Donlar synthesis of polyaspartate has only two steps and requires only heat and hydrolysis with sodium hydroxide.

Additional Problems

1. About 8000 homes

7. UV-B; need sunlight exposure to decompose; 399 kj/mol

APPENDIX

CH3CH2CH2CH2CH3

(b) H H H H H H H—C—C—C—C—C—C—I H H H H H H—C—H H • C—H H

(b) 1-butene

(c) 1,4-butadiene

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