Classify the following hydrocarbons, and draw a Lewis

Draw a Lewis structure, and classify each of the following compounds. The possible classifi- cations are as follows: alcohol ketone carboxylic acid ether aldehyde alkene (a) \(\mathrm{CH}_{2} \mathrm{CHCHO}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{COCH}_{2} \mathrm{CH}_{3}\) (d) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OCHCH}_{2}\) Equation transcription: Text transcription: {CH}_{2}{CHCHO} {CH}_{3}{CH}_{2}{CH}({OH}){CH}{3} {CH}_{3}{COCH}_{2}{CH}_{3} {CH}_{3}{CH}_{2}{OCHCH}_{2}

Problem 1P (a) Use your molecular models to make ethane, and compare the model with the preceding structures. (b) Make a model of propane (C3H8) and draw this model using dashed lines and wedges to represent bonds going back and coming forward.

Classify the following hydrocarbons, and draw a Lewis structure for each one. A compound may fit into more than one of the following classifications: alkane cycloalkane aromatic hydrocarbon alkene cycloalkene alkyne cycloalkyne (a) \(\left.\left(C H_{3} C H_{2} C H C H\right) C H_{2}\right)_{2}\) (b) \(\mathrm{CH}_{3} \mathrm{CHCHCH}_{2} \mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{CCCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}\) Equation transcription: Text transcription: (C H{3} C H_{2} C H C H) C H{2}){2} {CH}_{3}{CHCHCH}_{2}{CH}_{3} {CH}_{3}{CCCH}_{2}{CH}_{2}{CH}_{3}

Draw a Lewis structure, and classify each of the following compounds: (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CONHCH}_{3}\) (b) \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{2} \mathrm{NH}\) (c) \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHCOOCH}_{3}\) (d) \(\mathrm{CH}_{3} \mathrm{CHCHCOCl}\) (e) \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{2} \mathrm{O}\) (f) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CN}\) (g) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCH}_{2} \mathrm{CH}_{2} \mathrm{COOH}\) ________________ Equation Transcription: Text Transcription: CH_{3}CH_{2}CONHCH_{3} (CH_{3}CH_{2})_{2}NH (CH_{3})_{2}CHCOOCH_{3} CH_{3}CHCHCOCl (CH_{3}CH_{2})_{2}O CH_{3}CH_{2}CH_{2}CN (CH_{3})_{3}CCH_{2}CH_{2}COOH N-CH_{3} N-CH_{3} CH_{3} N-C-CH_{3} C-H COCH_{3}

For each of the following compounds, 1. Draw the Lewis structure. 2. Show how the bond dipole moments (and those of any nonbonding pairs of electrons) contribute to the molecular dipole moment. 3. Predict whether the compound will have a large \((>1\mathrm{\ D})\), small, or zero dipole moment. (a) \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{N}-\mathrm{CH}_{3}\) (b) \(\mathrm{CH}_{3}-\mathrm{CN}\) (c) \(\mathrm {C B r_{4}}\) ________________ Equation Transcription: Text Transcription: (1>D) CH_{3}-CH=N-CH_{3} CH_{3}-CN CBr_{4} CH_{3}-C-CH_{3} NC NC C=C CN CN ddot {N} Cl

Problem 33SP In pent-2-yne (CH3CCCH2CH3) there are four atoms in a straight line. Use dashed lines and wedges to draw a three dimensional representation of this molecule, and circle the four atoms that are in a straight line.

The \(\mathrm{N}-\mathrm{F}\) bond is more polar than the \(\mathrm{N}-\mathrm{H}\) bond, but \(\mathrm{NF}_{3}\) has a smaller dipole moment than \(\mathrm{NH}_{3}\), Explain this curious result. \(\mathrm{NH}_{3}\) \(\mathrm{NF}_{3}\) \(\mu=1.5\ \mathrm D\) \(\mu=0.2\ \mathrm D\) ________________ Equation Transcription: Text Transcription: N-F N-H NF_3 NH_3 NH_3 NF_3 mu=1.5 D mu=0.2 D

Two isomers of 1,2-dichloroethene are known. One has a dipole moment of 2.4 D; the other has zero dipole moment. Draw the two isomers and explain why one has zero dipole moment. \(\mathrm{CHCl}=\mathrm{CHCl}\) 1,2-dichloroethene ________________ Equation Transcription: Text Transcription: CHCl=CHCl

(a) Draw the structure of \( cis\text-\ \mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{2} \mathrm{CH}_{3}\) showing the pi bond with its proper geometry. (b) Circle the six coplanar atoms in this compound. (c) Draw the trans isomer, and circle the coplanar atoms. Are there still six? (d) Circle the coplanar atoms in the following structure. ________________ Equation Transcription: Text Transcription: cis-CH_{3}-CH=CH-CH_{2}CH_{3} CH_3

N-Methylpyrrolidine has a boiling point of \(81^{\circ} \mathrm{C}\), and piperidine has a boiling point of \(106^{\circ} \mathrm{C}\). (a) Explain this large difference (\(25^{\circ} \mathrm{C}\)) in boiling point for these two isomers. (b) Tetrahydropyran has a boiling point of \(88^{\circ} \mathrm{C}\), and cyclopentanol has a boiling point of \(141^{\circ} \mathrm{C}\). These two isomers have a boiling point difference of \(53^{\circ} \mathrm{C}\). Explain why the two oxygen-containing isomers have a much larger boiling point difference than the two amine isomers. (c) N,N-Dimethylformamide has a boiling point of \(150^{\circ} \mathrm{C}\), and N-methylacetamide has a boiling point of \(206^{\circ} \mathrm{C}\), for a difference of \(56^{\circ} \mathrm{C}\). Explain why these two nitrogen-containing isomers have a much larger boiling point difference than the two amine isomers. Also explain why these two amides have higher boiling points than any of the other four compounds shown (two amines, an ether, and an alcohol). Equation Transcription: Text Transcription: 81^{o}C 106^{o}C 25^{o}C 88^{o}C 141^{o}C 53^{o}C 150^{o}C 206^{o}C 56^{o}C N-CH_3 81^{o}C 88^{o}C H-C-N CH_3 CH_3 150^{o}C N-H 106^{o}C OH 141^{o}C CH_{3}-C-N CH_3 206^{o}C

(a) Predict the hybridization of the oxygen atom in water \(\mathrm{H}_{2} \mathrm{O}\), Draw a picture of its three-dimensional structure, and explain why its bond angle is \(104.5^{\circ}\). (b) The electrostatic potential maps for ammonia and water are shown here. The structure of ammonia is shown within its EPM. Note how the lone pair creates a region of high electron potential (red), and the hydrogens are in regions of low electron potential (blue). Show how your three-dimensional structure of water corresponds with its EPM. ________________ Equation Transcription: Text Transcription: H_{2}O 104.5^o NH_3 H_{2}O

Diethyl ether and butan-1-ol are isomers, and they have similar solubilities in water. Their boiling points are very different, however. Explain why these two compounds have similar solubility properties but dramatically different boiling points. \(\mathrm{CH}_{3} \mathrm{CH}_{2}-\mathrm{O}-\mathrm{CH}_{2} \mathrm{CH}_{3}\) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2}-\mathrm{OH}\) diethyl ether, bp \(35\ ^{\circ}\mathrm{C}\) butan-1-ol, bp \(118\ ^{\circ}\mathrm{C}\) 8.4 mL dissolves in 100 mL \(\mathrm{H}_{2} \mathrm{O}\) 9.1 mL dissolves in 100 mL \(\mathrm{H}_{2} \mathrm{O}\) Equation Transcription: Text Transcription: CH_{3}CH_{2}-O-CH_{2}CH_{3} 35 o^C H_{2}O CH_{3}CH_{2}CH_{2}CH_{2}-OH 118 o^C H_{2}O

Draw orbital pictures of the pi bonding in the following compounds: (a) \(\mathrm{CH}_{3} \mathrm{COCH}_{3}\) (b) \(\mathrm {HCN}\) (c) \(\mathrm {CH_2=CH-CHCHCN}\) (d) \(\mathrm{CH}_{3} \mathrm{C} \equiv \mathrm{CCHO}\) (e) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{C}=\mathrm{CHCH}_{3}\) Equation Transcription: Text Transcription: CH3COCH3 HCN CH2=CH-CHCHCN CH3CCCHO CH3CH=C=CHCH3

Predict the hybridization, geometry, and bond angles for the central atoms in: (a) but-2-ene, \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCH}_{3}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{NH}\) Equation Transcription: Text Transcription: CH_{3}CH=CHCH_3 CH_{3}CH=NH

Circle the functional groups in the following structures. State to which class (or classes) of compounds the structure belongs. Equation Transcription: Text Transcription: COOH CHO N-H CH_{2}OCH_{3} CN NH_{2} CH_{3}-CH-COOCH_{3} H_{2}N-CH-COOH CH_{2}-OH

Problem 16P Draw the hydrogen bonding that takes place between: (a) Two molecules of ethanol. (b) Two molecules of propylamine. (c) A molecule of dimethyl ether and two molecules of water. (d) Two molecules of trimethylamine and a molecule of water.

Predict the hybridization, geometry, and bond angles for the carbon and nitrogen atoms in acetonitrile (\(\mathrm{CH}_{3}-\mathrm{C} \equiv \mathrm{N}\):). Equation Transcription: Text Transcription: CH_{3}-C{equiv}N

Problem 24SP Give a definition and an example for each class of organic compounds. (a) alkane (b) alkene (c) alkyne (d) alcohol (e) ether (f) ketone (g) aldehyde (h) aromatic hydrocarbon (i) carboxylic acid (j) ester (k) amine (l) amide (m) nitrile

Problem 5P 1. Draw a Lewis structure for each compound. 2. Label the hybridization, geometry, and bond angles around each atom other than hydrogen. 3. Draw a three-dimensional representation (using wedges and dashed lines) of the structure. (a)CO 2 (b) CH 3 OCH 3 (c)(CH 3 ) 3 O + (d) CH 3COOH (e) CH 3 CCH (f) CH 3 CHNCH 3 (g) H2CCO

For each pair of compounds, circle the compound you expect to have the higher boiling point. Explain your reasoning. (a) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}-\mathrm{C}\left(\mathrm{CH}_{3}\right)_{3}\) and \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CH}-\mathrm{CH}_{2} \mathrm{CH}_{2}-\mathrm{CH}\left(\mathrm{CH}_{3}\right)_{2}\) (b) \(\mathrm{CH}_{3}\left(\mathrm{CH}_{2}\right)_{6} \mathrm{CH}_{3}\) and \(\mathrm{CH}_{3}\left(\mathrm{CH}_{2}\right)_{5} \mathrm{CH}_{2} \mathrm{OH}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OCH}_{2} \mathrm{CH}_{3}\) or \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) (d) \(\mathrm{HOCH}_{2}-\left(\mathrm{CH}_{2}\right)_{4}-\mathrm{CH}_{2} \mathrm{OH}\) and \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCH}(\mathrm{OH}) \mathrm{CH}_{3}\) (e) \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2}\right)_{2} \mathrm{NH}\) and \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{3} \mathrm{~N}\) Equation Transcription: Text Transcription: (CH_{3})_{3}C-C(CH_{3})_{3} (CH_{3})_{2}CH-CH_{2}CH_{2}-CH(CH_{3})_{2} CH_{3}(CH_{2})_{6}CH_{3} CH_{3}(CH_{2})_{8}CH_{2}OH CH_{3}CH_{2}OCH_{2}CH_{3} CH_{3}CH_{2}CH_{2}CH_{2}OH HOCH_{2}-(CH_{2})_{4}-CH_{2}OH (CH_{3})_{3}CCH(OH)CH_{3} (CH_{3}CH_{2}CH_{2})_{2}NH (CH_{3}CH_{2})_{3}N NH NH_2

Circle the functional groups in the following structures. State to which class (or classes) of com- pounds the structure belongs. (a) \(\mathrm{CH}_{2}=\mathrm{CHCH}_{2} \mathrm{COOCH}_{3}\) (b) \(\mathrm{CH}_{3} \mathrm{OCH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{CHO}\) (d) \(\mathrm{CH}_{3} \mathrm{CONH}_{2}\) (e) \(\mathrm{CH}_{3} \mathrm{NHCH}_{3}\) (f) \(\mathrm{RCOOH}\) Equation Transcription: Text Transcription: CH_{2}=CHCH_{2}COOCH_{3} CH_{3}OCH_{3} CH_{3}CHO CH_{3}CONH_{2} CH_{3}NHCH_{3} RCOOH CH_{2}OH CN HO CH_{2}OH OH HO CH_{3} CH_{3} CH_{3} C_{16}H_33 CH_3

Give the relationships between the following pairs of structures. The possible relationships are: same compound, cis-trans isomers, constitutional (structural) isomers, not isomers (different molecular formula). (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}\) and \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CH}\) (b) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{2} \mathrm{Cl}\) and \(\mathrm{CHCl}=\mathrm{CH}-\mathrm{CH}_{3}\) Equation Transcription: Text Transcription: CH_{3}CH_{2}CH_{2}CH_{3} (CH_{3})_{3}CH CH_{2}=CH-CH_{2}Cl CHCl=CH-CH_{3} CH_{3} CH_{3} CH_{3} CH_{3} CH_{3} CH_{3} CH_{3} C=CH_{2} CH_{3} CH_{3} CH_{3} CH_{3} CH_{2}-CH_{2} CH_{2}CH_{3} CH_{3} CH_{2}-CH_{2} CH_{2}CH_{3}

Circle the member of each pair that is more soluble in water. (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OCH}_{2} \mathrm{CH}_{3} \text { or } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OCH}_{2} \mathrm{CH}_{3} \text { or } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{NHCH}_{3} \text { or } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}\) (d) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH} \text { or } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) Equation Transcription: Text Transcription: CH_{3}CH_{2}OCH_{2}CH_{3} or CH_{3}CH_{2}CH_{2}CH_{2}CH_{3} CH_{3}CH_{2}OCH_{2}CH_{3} or CH_{3}CH_{2}CH_{2}OH CH_{3}CH_{2}NHCH_{3} or CH_{3}CH_{2}CH_{2}CH_{3} CH_{3}CH_{2}OH or CH_{3}CH_{2}CH_{2}CH_{2}OH H_{3}C CH_{3}

For each of these ions, draw the important resonance forms and predict which resonance form is likely to be the major contributor. Equation Transcription: Text Transcription: CH_2^+ CH_2^- HN CH_2^+

Which of the following pure compounds can form hydrogen bonds? Which can form hydrogen bonds with water? Which ones do you expect to be soluble in water? (a) \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{2} \mathrm{NH}\) (b) \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{3} \mathrm{~N}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) (d) \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2}\right)_{2} \mathrm{O}\) (e) \(\mathrm{CH}_{3}\left(\mathrm{CH}_{2}\right)_{3} \mathrm{CH}_{3}\) (f) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{2} \mathrm{CH}_{3}\) (g) \(\mathrm{CH}_{3} \mathrm{COCH}_{3}\) (h) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH}\) (i) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CHO}\) Equation Transcription: Text Transcription: (CH_{3}CH_{2})_{2}NH (CH_{3}CH_{2})_{3}CH_{3} CH_{3}CH_{2}CH_{2}OH (CH_{3}CH_{2}CH_{2})_{2}O CH_{3}(CH_{2})_{3}CH_{3} CH_{2}=CH-CH_{2}CH_{3} CH_{3}COCH_{3} CH_{3}CH_{2}COOH CH_{3}CH_{2}CHO CH_{3}-C-NH_{2}

Which of the following compounds show cis-trans isomerism? Draw the cis and trans isomers of the ones that do. (a) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCH}_{3}\) (b) \(\mathrm{CH}_{3}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{2}=\mathrm{C}\left(\mathrm{CH}_{3}\right)_{2}\) (f) \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{N}-\mathrm{CH}_{3}\) Equation Transcription: Text Transcription: CH_{3}CH=CHCH_{3} CH_{3}-CC-CH_{3} CH2=C(CH_{3})_{2} CH_{3}-CH=C-CH_{2}-CH_{3} CH_{2}CH_{2}CH_{3} CH_{3}-CH=N-CH_{3}

Problem 36SP Sulfur dioxide has a dipole moment of 1.60 D. Carbon dioxide has a dipole moment of zero, even though C-O bonds are more polar than S-O bonds. Explain this apparent contradiction.

Predict which compound in each pair has the higher boiling point. Explain your prediction. (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OCH}_{3} \text { or } \mathrm{CH}_{3} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{3}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3} \text { or } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3} \text { or }\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHCH}_{2} \mathrm{CH}_{3}\) (d) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3} \text { or } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}\) Equation Transcription: Text Transcription: CH_{3}CH_{2}OCH_{3} or CH_{3}CH(OH)CH_{3} CH_{3}CH_{2}CH_{2}CH_{3} or CH_{3}CH_{2}CH_{2}CH_{2}CH_{3} CH_{3}CH_{2}CH_{2}CH_{2}CH_{3} or (CH_{3})_{2}CHCH_{2}CH_{3} CH_{3}CH_{2}CH_{2}CH_{2}CH_{3} or CH_{3}CH_{2}CH_{2}CH_{2}CH_{2}Cl

For each of the following compounds: 1. Draw the Lewis structure. 2. Show how the bond dipole moments (and those of any nonbonding pairs of electrons) contribute to the molecular dipole moment. 3. Predict whether the compound has a large ( > 1 D ), small, or zero dipole moment. (a) \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\) (b) \(\mathrm{CH}_{3} \mathrm{~F}\) (c) \(\mathrm{CF}_{4}\) (d) \(\mathrm{CH}_{3} \mathrm{OH}\) (e) \(\mathrm{O}_{3}\) (f) \(\mathrm{HCN}\) (g) \(\mathrm{CH}_{3} \mathrm{CHO}\) (h) \(\mathrm{H}_{2} \mathrm{C}=\mathrm{NH}\) (i) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}\) (j) \(\mathrm{CH}_{2}=\mathrm{CHCl}\) (k) \(\mathrm{BF}_{3}\) (l) \(\mathrm{BeCl}_{2}\) (m) \(\mathrm{NH}_{4}^{+}\) Equation Transcription: Text Transcription: CH_{2}Cl_{2} CH_{3}F CF_{4} CH_{3}OH O_{3} HCN CH_{3}CHO H_{2}C=NH (CH_{3})_{3}N CH_{2}=CHCl BF_{3} BeCl_{2} NH_{4}^{+}

Which of the following compounds show cis-trans isomerism? Draw the cis and trans isomers of those that do. (a) \(\mathrm{CHF}=\mathrm{CHF}\) (b) \(\mathrm{F}_{2} \mathrm{C}=\mathrm{CH}_{2}\) (c) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{2}-\mathrm{CH}_{3}\) Equation Transcription: Text Transcription: CHF=CHF F_{2}C=CH_{2} CH_{2}=CH-CH_{2}-CH_{3} CHCH_{3} CHCHCH_{3} CHCH_{3}

Give the relationship between the following pairs of structures. The possible relationships are: same compound constitutional isomers (structural isomers) cis-trans isomers not isomers (different molecular formula) (g) \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{3} \text { and } \mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{3}\) (h) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3} \text { and } \mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{2} \mathrm{CH}_{3}\) (j) \(\mathrm{CH}_{2}=\mathrm{CHCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3} \text { and } \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}_{2}\) Equation Transcription: Text Transcription: CH_{3}CH_{2}CHCH_{2}CH_{3} CH_{3}CH_{2}CHCH_{2}CH_{2}CH_{3} CH_{2}CH_{3} CH_{3} Br C=C Br Br C=C Br Br C=C Br Br C=C Br Br C=C Br Cl H-C-C-H Cl H-C-C-H Cl Cl H-C-C-H CH_{3} CH_{3} H-C-C-CH_{3} CH_{3} CH_{3}-CH_{2}-CH_{2}-CH_{3} and CH_{3}-CH=CH-CH_{3} CH_{2}=CH-CH_{2}CH_{2}CH_{3} and CH_{3}-CH=CH-CH_{2}CH_{3} CH_{2}=CHCH_{2}CH_{2}CH_{3} and CH_{3}CH_{2}CH_{2}CH=CH_{2} CH_{3} CH_{3} CH_{3} CH_{3} CH_{3} CH_{3}

For each of the following compounds and ions, 1. Draw a Lewis structure. 2. Show the kinds of orbitals that overlap to form each bond. 3. Give approximate bond angles around each atom except hydrogen. (a) \({\left[\mathrm{NH}_{2}\right]^{-}}\) (b) \({\left[\mathrm{CH}_{2} \mathrm{OH}\right]^{+}}\) (c) \(\mathrm{CH}_{2}=\mathrm{N}-\mathrm{CH}_{3}\) (d) \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}_{2}\) (e) \(\mathrm{HC} \equiv \mathrm{C}-\mathrm{CHO}\) (f) \(\mathrm{H}_{2} \mathrm{~N}-\mathrm{CH}_{2}-\mathrm{CN}\) Equation Transcription: Text Transcription: [NH_{2}]^- [CH_{2}OH]^+ CH_{2}=N-CH_{3} CH_{3}-CH=CH_{2} HC{equiv}C-CHO H_{2}N-CH_{2}-CN CH_{3}-C-OH

The double bond has a dipole moment of about 2.4 D and a bond length of about \(1.23 \AA\) (a) Calculate the amount of charge separation in this bond. (b) Use this information to evaluate the relative importance of the following two resonance contributors: (R is a general symbol for a carbon-containing group.) Equation Transcription: Å Text Transcription: C=O 1.23 {AA} O^- C^+

In most amines, the nitrogen atom is \(s p^{3}\) hybridized, with a pyramidal structure and bond angles close to \(109^{\circ}\). In urea, both nitrogen atoms are found to be planar, with bond angles close to \(120^{\circ}\). Explain this surprising finding. (Hint: Consider resonance forms and the overlap needed in them.) Equation Transcription: Text Transcription: sp^3 109^o 120^o H_{2}ddot{N}-C-ddot{N}H_2

Predict the hybridization and geometry of the carbon and nitrogen atoms in the following ions. (Hint: Resonance.) Equation Transcription: Text Transcription: CH_{3}-C-CH_{2} H_{2}N-CH=CH-CH_{2}^{+} ^{-}CH_2-C{equiv}N

Allene, \(\mathrm{CH}_{2}=\mathrm{C}=\mathrm{CH}_{2}\), has the structure shown below. Explain how the bonding in allene requires the two \(=\mathrm{CH}_{2}\) groups at its ends to be at right angles to each other. Equation Transcription: Text Transcription: CH_{2}=C=CH_{2} =CH_{2} C=C=C

For each pair of structures, determine whether they represent different compounds or a single compound. Equation Transcription: Text Transcription: H_{3}C CH_{2}CH_{3} CH_{3} H_{3}C CH_{3} CH_{2}CH_{3} H_{3}C CH_{2}CH_{3} CH_{3} H_{3}C CH_{3} CH_{2}CH_{3} Br C=C Cl Cl C=C Br Br C-C Cl Br C-C Cl

Two compounds with the formula \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{N}-\mathrm{CH}_{3}\) are known. (a) Draw a Lewis structure for this molecule, and label the hybridization of each carbon and nitrogen atom. (b) What two compounds have this formula? (c) Explain why only one compound with the formula \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CNCH}_{3}\) is known. Equation Transcription: Text Transcription: CH_{3}-CH=N-CH_{3} (CH_{3})_{2}CNCH_{3}

If the carbon atom in \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\) were flat, there would be two stereoisomers. The carbon atom in \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\) is actually tetrahedral. Make a model of this compound, and determine whether there are any stereoisomers of \(\mathrm{CH}_{2} \mathrm{Cl}_{2}\). Equation Transcription: Text Transcription: CH_{2}Cl_{2} CH_{2}Cl_{2} CH_{2}Cl_{2}

Problem 26SP Cyclopropane (C3H6, a three-membered ring) is more reactive than most other cycloalkanes. (a) Draw a Lewis structure for cyclopropane. (b) Compare the bond angles of the carbon atoms in cyclopropane with those in an acyclic (noncyclic) alkane. (c) Suggest why cyclopropane is so reactive.

For each of the following compounds, 1. Give the hybridization and approximate bond angles around each atom except hydrogen. 2. Draw a three-dimensional diagram, including any lone pairs of electrons. (a) \(\mathrm{H}_{3} \mathrm{O}^{+}\) (b) \({ }^{-} \mathrm{OH}\) (c) \(\mathrm{CH}_{2} \mathrm{CHCN}\) (d) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}\) (e) \({\left[\mathrm{CH}_{3} \mathrm{NH}_{3}\right]^{+}}\) (f) \(\mathrm{CH}_{3} \mathrm{COOH}\) (g) \(\mathrm{CH}_{3} \mathrm{CHNH}\) (h) \(\mathrm{CH}_{3} \mathrm{OH}\) (i) \(\mathrm{CH}_{2} \mathrm{O}\) Equation Transcription: Text Transcription: H_{3}O^+ ^{-}OH CH_{2}CHCN (CH_{3})_{3}N [CH_{3}NH_{3}]^+ CH_{3}COOH CH_{3}CHNH CH_{3}OH CH_{2}O

Dimethyl sulfoxide (DMSO) has been used as an anti-inflammatory rub for race horses. DMSO and acetone appear to have similar structures, but the carbon atom in acetone is planar, while the sulfur atom in DMSO is pyramidal. Draw Lewis structures for DMSO and acetone, predict the hybridizations, and explain these observations. Equation Transcription: Text Transcription: (DMSO) DMSO DMSO DMSO CH_{3}-S-CH_{3} CH_{3}-C-CH_{3} DMSO

Many naturally occurring compounds contain more than one functional group. Identify the functional groups in the following compounds: (a) Penicillin G is a naturally occurring antibiotic. (b) Dopamine is the neurotransmitter that is deficient in Parkinson’s disease. (c) Capsaicin gives the fiery taste to chili peppers. (d) Thyroxine is the principal thyroid hormone. (e) Testosterone is a male sex hormone. Equation Transcription: Text Transcription: CH_{2}-C-NH COOH HO HO CH_{2}CH_{2} NH_{2} CH_{3}O HO _{H}^N HO CH_{2}-CH-COOH NH_{2} OH