Use electronegativities to predict the direction of the

Problem 3P Write Lewis structures for the following molecular formulas. (a) N 2 (b) HCN (c) HONO (d) CO 2 (e) CH 3 CHNH (f) HCO 2 H (g) C 2 H 3 Cl (h) HNNH (i) C 3 H 6(one double bond) (j) C3H4 (two double bonds) (k) C3H4 (one triple bond)

Problem 2P Draw Lewis structures for the following compounds. (a) ammonia, NH3 (b) water, H2O (c) hydroniumion, H3O+ (d) propane, C3H8 (e) dimethylamine,CH3NHCH3 (f) diethyl ether, CH3CH2OCH2CH3 (g) 1-chloropropane, CH3CH2CH2Cl (h) propan-2-ol,CH3CH(OH)CH3 (i) borane, BH3 (j) boron trifluoride, BF3 Explain what is unusual about the bonding in the compounds in parts (i) and (j).

Problem 4P Circle any lone pairs (pairs of nonbonding electrons) in the structures you drew for Problem 1-3. P1-3- Write Lewis structures for the following molecular formulas. (a) N 2 (b) HCN (c) HONO (d) CO 2 (e) CH 3 CHNH (f) HCO 2 H (g) C 2 H 3 Cl (h) HNNH (i) C 3 H 6(one double bond) (j) C3H4 (two double bonds) (k) C3H4 (one triple bond)

Give Lewis structures corresponding to the following line–angle structures. Give the molecular formula for each structure. Equation Transcription: Text Transcription: H^N H^N OH CHO

(a) Nitrogen has relatively stable isotopes (half-life greater than 1 second) of mass numbers 13, 14, 15, 16, and 17. (All except \({ }^{14} N \text { and }{ }^{15} N\) are radioactive.) Calculate how many protons and neutrons are in each of these isotopes of nitrogen. (b) Write the electronic configurations of the third-row elements shown in the partial periodic table in Figure 1-5. Equation Transcription: Text Transcription: ^14 N and ^15 N

Repeat Problem 1-9, this time drawing line–angle structures for compounds \(\text { (a) }\) through \(\text { (h) }\) Equation Transcription: Text Transcription: (a) (h)

Problem 12P Compute the empirical and molecular formulas for each of the following elemental analyses. In each case, propose at least one structure that fits the molecular formula. C H N C1 MW (a) 40.0% 6.67% 0 0 90 (b) 32.0% 6.67% 18.7% 0 75 (c) 25.6% 4.32% 15.0% 37.9% 93 (d) 38.4% 4.80% 0 56.8% 125

Calculate the pH of the following solutions. (a) 5.00 g of HBr in 100 mL of aqueous solution (b) 1.50 g of NaOH in 50 mL of aqueous solution

Ammonia appears in Table 1-5 both as an acid and as a conjugate base. (a) Explain how ammonia can act as both an acid and a base. Which of these roles does it commonly fill in aqueous solutions? (b) Show how water can serve as both an acid and a base. (c) Calculate \(K_{a} \text { and } p K_{a}\) for the hydronium ion, \(\mathrm{H}_{3} \mathrm{O}^{+}\). (d) Show how methanol \(\left(\mathrm{CH}_{3} \mathrm{OH}\right)\) can serve as both an acid and a base. Write an equation for the reaction of methanol with sulfuric acid. Equation Transcription: Text Transcription: Ka and pKa H3O+ (CH3OH)

Solved Problem 1-5(c) showed protonation of the double-bonded oxygen in acetic acid. Show the product of protonation on the other \((-O H)\) oxygen. Explain why protonation of the double-bonded oxygen is favored. Equation Transcription: Text Transcription: (-OH)

(a) Rank ethanol, methylamine, and acetic acid in decreasing order of acidity. (b) Rank ethanol, methylamine (\(pK_b\) 3.36), and ethoxide ion (\(CH_3CH_2O^-\)) in decreasing order of basicity. In each case, explain your ranking.

Write equations for the following acid–base reactions. Use the information in Table 1-5 to predict whether the equilibrium will favor the reactants or the products. (a) \(\mathrm{HCOOH+}^{-} \mathrm{CN}\) (b) \(\mathrm{CH}_{3} \mathrm{COO}^{-}+\mathrm{CH}_{3} \mathrm{OH}\) (c) \(\mathrm{CH}_{3} \mathrm{OH}+\mathrm{NaNH}_{2}\) (d) \(\mathrm{NaOCH}_{3}+\mathrm{HCN}\) (e) \(\mathrm{HCI}+\mathrm{H}_{2} \mathrm{O}\) (f) \(\mathrm{H}_{3} \mathrm{O}^{+}+\mathrm{CH}_{3} \mathrm{O}^{-}\) Equation Transcription: Text Transcription: HCOOH+ -CN CH_3COO-+CH_3OH CH_3OH+NaNH_2 NaOCH_3+HCN HCI+H_2O H_3O++CH_3O-

Write equations for the following acid–base reactions. Label the conjugate acids and bases, and show any resonance stabilization. Predict whether the equilibrium favors the reactants or products. If in doubt, you can consult Appendix 4 for acids not shown in Table 1-5. (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}+\mathrm{CH}_{3} \mathrm{NH}^{-}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH}+\mathrm{CH}_{3} \mathrm{NHCH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{OH}+\mathrm{H}_{2} \mathrm{SO}_{4}\) (d) \(\mathrm{NaOH}+\mathrm{H}_{2} \mathrm{~S}\) (e) \(\mathrm{CH}_{3} \mathrm{NH}_{3}^{+}+\mathrm{CH}_{3} \mathrm{O}^{-}\) (f) \(\mathrm{CH}_{3} \mathrm{O}^{-}+\mathrm{CH}_{3} \mathrm{COOH}\) (g) \(\mathrm{CH}_{3} \mathrm{SO}_{3}^{-}+\mathrm{CH}_{3} \mathrm{COOH}\) (h) \(\mathrm{CF}_{3} \mathrm{COOH}+\mathrm{CH}_{3} \mathrm{COO}^{-}\) (i) \(\mathrm{CH}_{3} \mathrm{CHFCOOH}+\mathrm{FCH}_{2} \mathrm{CH}_{2} \mathrm{COO}^{-}\) (j) \(\mathrm{CF}_{3} \mathrm{CH}_{2} \mathrm{O}^{-}+\mathrm{FCH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) Equation Transcription: Text Transcription: CH_3CH_2OH+CH_3NH- CH_3CH_2COOH+CH_3NHCH_3 CH_3OH+H_2SO_4 NaOH+H_2S CH_3NH_3++CH_3O- CH_3O-+CH_3COOH CH_3SO_3-+CH_3COOH CF_3COOH+CH_3COO- CH_3CHFCOOH+FCH_2CH_2COO- CF_3CH_2O-+FCH_2CH_2OH

(a) Draw the resonance forms for \(\mathrm{SO}_{2}\) (bonded O—S—O) (b) Draw the resonance forms for ozone (bonded O—O—O) (c) Sulfur dioxide has one more resonance form than ozone. Explain why this structure is not possible for ozone.

In the following acid–base reactions, 1. determine which species are acting as electrophiles (acids) and which are acting as nucleophiles (bases). 2. use the curved-arrow formalism to show the movement of electron pairs in these reactions, as well as the imaginary movement in the resonance hybrids of the products. 3. indicate which reactions are best termed Brønsted–Lowry acid–base reactions.

Problem 21SP Name the element that corresponds to each electronic configuration. (a) 1s22s22p2 (b) 1s22s22p4 (c) 1s22s22p63s23p3 (d) 1s22s22p63s23p5

Problem 22SP There is a small portion of the periodic table that you must know to do organic chemistry. Construct this part from memory, using the following steps. (a) From memory, make a list of the elements in the first two rows of the periodic table, together with their numbers of valence electrons. (b) Use this list to construct the first two rows of the periodic table. (c) Organic compounds often contain sulfur, phosphorus, chlorine, bromine, and iodine. Add these elements to your periodic table.

Problem 23SP For each compound, state whether its bonding is covalent, ionic, or a mixture of covalent and ionic. (a) NaCl (b) NaOH (c) CH3Li (d) CH2Cl2 (e) NaOCH3 (f) HCO2Na (g) CF4

Problem 24SP (a) Both PCl3 and PCl5 are stable compounds. Draw Lewis structures for these two compounds. (b) NCl 3 is a known compound, but all attempts to synthesize have failed. Draw Lewis structures for and a hypothetical NCl5, and explain why NCl5 is an unlikely structure.

Problem 25SP Draw a Lewis structure for each species. (a) N 2 H 4 (b) N 2 H 2 (c) (CH 3 ) 2 NH 2 Cl (d) CH 3 CN (e) CH3CHO (f) CH3S(O)CH3 (g) H 2 SO 4 (h) CH 3 NCO (i) CH 3 OSO 2 OCH 3 (j) CH 3 C(NH)CH 3 (k) (CH 3 ) 3 CNO

Problem 26SP Draw a Lewis structure for each compound. Include all nonbonding pairs of electrons. (a) CH3COCH2CHCHCOOH (b) NCCH2COCH2CHO (c) CH2CHCH1OH2CH2CO2H (d) CH2CHC(CH3)CHCOOCH3

Problem 27SP Draw a line–angle formula for each compound in Problem 1-26. P-26 - Draw a Lewis structure for each compound. Include all nonbonding pairs of electrons. (a) CH3COCH2CHCHCOOH (b) NCCH2COCH2CHO (c) CH2CHCH1OH2CH2CO2H (d) CH2CHC(CH3)CHCOOCH3

Draw Lewis structures for (a) two compounds of formula \(C_{4} H_{10}\) (b) two compounds of formula \(\mathrm{C}_{2} \mathrm{H}_{6} \mathrm{O}\) (c) two compounds of formula \(C_{2} H_{7} N\) (d) three compounds of formula \(\mathrm{C}_{2} \mathrm{H}_{7} \mathrm{NO}\) (e) three compounds of formula \(\mathrm{C}_{3} \mathrm{H}_{8} \mathrm{O}_{2}\) (f) three compounds of formula \(\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}\)

Problem 29SP Draw a complete structural formula and a condensed structural formula for (a) three compounds of formula C3H8O (b) five compounds of formula C3H6O

Some of the following molecular formulas correspond to stable compounds. When possible, draw a stable structure for each formula. Can you propose a general rule for the numbers of hydrogen atoms in stable hydrocarbons?

Give the molecular formula of each compound shown in Problem 1-31.

Draw complete Lewis structures, including lone pairs, for the following compounds. Equation Transcription: Text Transcription: H_2N COOH CHO SO_3H OCH_3

Problem 33SP Compound X, isolated from lanolin (sheep’s wool fat), has the pungent aroma of dirty sweatsocks. A careful analysis showed that compound X contains 62.0% carbon and 10.4% hydrogen. No nitrogen or halogen was found. (a) Compute an empirical formula for compound X. (b) A molecular weight determination showed that compound X has a molecular weight of approximately 117. Find the molecular formula of compound X. (c) Many possible structures have this molecular formula. Draw complete structural formulas for four of them.

For each of the following structures, 1. Draw a Lewis structure; fill in any nonbonding electrons. 2. Calculate the formal charge on each atom other than hydrogen. All are electrically neutral except as noted.

Problem 35SP 1. From what you remember of electronegativities, show the direction of the dipole moments of the following bonds. 2. In each case, predict whether the dipole moment is relatively large (electronegativity difference ) or small. (a) C-Cl (b) C-H (c) C-Li (d) C-N (e) C-O (f) C-B (g) C-Mg (h) N-H (i) O-H (j) C-Br

Determine whether the following pairs of structures are actually different compounds or simply resonance forms of the same compounds.

All of the following compounds can react as acids. Without using a table of acidities, rank them in order of increasing acidity. Explain your ranking. (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{SO}_{3} \mathrm{H}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{OH}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH}\) (d) \(\mathrm{CH}_{3} \mathrm{CHCICOOH}\) (e) \(\mathrm{CICH}_{3} \mathrm{CH}_{3} \mathrm{COOH}\) Equation Transcription: Text Transcription: CH_3CH_2SO_3H CH_3CH_2OH CH_3CH_2COOH CH_3CHCICOOH CICH_3CH_3COOH

Draw the important resonance forms to show the delocalization of charges in the following ions.

The following compound can become protonated on any of the three nitrogen atoms. One of these nitrogens is much more basic than the others, however. (a) Draw the important resonance forms of the products of protonation on each of the three nitrogen atoms. (b) Determine which nitrogen atom is the most basic. Equation Transcription: Text Transcription: CH_3 NH C NH NH_2

In the following sets of resonance forms, label the major and minor contributors and state which structures would be of equal energy. Add any missing resonance forms.

For each pair of ions, determine which ion is more stable. Use resonance forms to explain your answers.

Rank the following species in order of increasing acidity. Explain your reasons for ordering them as you do. \(\text { HF } \quad \mathrm{NH}_{3} \quad \mathrm{H}_{2} \mathrm{SO}_{4} \quad \mathrm{CH}_{3} \mathrm{OH} \quad \mathrm{CH}_{3} \mathrm{COOH} \quad \mathrm{H}_{3} \mathrm{O}^{+} \quad \mathrm{H}_{2} \mathrm{O}\)

Problem 43SP Rank the following species in order of increasing basicity. Explain your reasons for ordering them as you do. NH3 CH3O- H2O CH3COO- NaOH NH2- HSO4-

The \(K_{a}\) of phenylacetic acid is \(5.2 \times 10^{-5}\), and the \(p K_{a}\) of propionic acid is 4.87. (a) Calculate the \(p K_{a}\) of phenylacetic acid and the \(K_{a}\) of propionic acid. (b) Which of these is the stronger acid? Calculate how much stronger an acid it is. (c) Predict whether the following equilibrium will favor the reactants or the products. Equation Transcription: Text Transcription: Ka 5.2 X 10-5 pKa pKa Ka

Label the reactants in these acid–base reactions as Lewis acids (electrophiles) or Lewis bases (nucleophiles). Use curved arrows to show the movement of electron pairs in the reactions.

Predict the products of the following acid–base reactions.

The following compounds are listed in increasing order of acidity. In each case, the most acidic proton is shown in red. (a) Show the structure of the conjugate base of each acid, including any resonance forms. (b) Explain why \(X\) is a stronger acid than \(W\) (c) Explain why \(Y\) is a stronger acid than \(X\) (d) Explain why \(Z\) is a stronger acid than \(Y\) Equation Transcription: Text Transcription: CH_2 NH OH W,pKa=25 X,pKa=23 Y,pKa=8.8 Z,pKa=4.2 X W Y X Z Y

Amides such as acetamide are much weaker bases than amines, such as ethylamine \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{NH}_{2}\right)\). (a) Use resonance forms to show why the nonbonding electrons on the nitrogen atom of the amide are very weakly basic. (b) Strong acid is required to protonate the amide. Predict where acetamide will undergo protonation, and use resonance forms to show why the site you have chosen is more basic. (Hint: To compare basicities, compare the stabilities of the conjugate acids.) Equation Transcription: Text Transcription: (CH_3CH_2NH_2)

Methyllithium \(\left(\mathrm{CH}_{3} \mathrm{Li}\right)\) is often used as a base in organic reactions. (a) Predict the products of the following acid–base reaction. \(\mathrm{CH}_{3} \mathrm{CH}_{2}-\mathrm{OH}+\mathrm{CH}_{3}-\mathrm{Li} \rightarrow\) (b) What is the conjugate acid of \(\mathrm{CH}_{3} \mathrm{Li}\)? Would you expect \(\mathrm{CH}_{3} \mathrm{Li}\) to be a strong base or a weak base? Equation Transcription: Text Transcription: (CH_3Li) CH_3CH_2-OH+CH_3-Li \rightarrow CH_3Li CH_3Li

The following compounds can all react as acids. (a) For each compound, show its conjugate base. Show any resonance forms if applicable. (b) Rank the conjugate bases in the order you would predict, from most stable to least stable. (c) Rank the original compounds in order, from strongest acid to weakest acid.

The following compounds can all react as bases. \(\mathrm{CH}_{3} \mathrm{CH}_{2}-\mathrm{NH}_{2} \quad \mathrm{CH}_{3}-\mathrm{C}-\mathrm{NH}_{2} \quad \mathrm{NaOH} \quad \mathrm{CH}_{3} \mathrm{CH}_{2}-\mathrm{OH} \quad \mathrm{NaNH}_{2}\) (a) For each compound, show its conjugate acid. Show any resonance forms if applicable. (b) Rank the conjugate acids in the order you would predict, from most stable to least stable. (c) Rank the original compounds in order, from strongest base to weakest base. Equation Transcription: Text Transcription: CH3CH2-NH2 CH3-C-NH2 NaOH CH3CH2-OH NaNH2

The following compounds can all react as acids. (a) For each compound, show its conjugate base. Show any resonance forms if applicable. (b) Rank the conjugate bases in the order you would predict, from most stable to least stable. (c) Rank the original compounds in order, from strongest acid to weakest acid. Equation Transcription: Text Transcription: CH3-C-OH CH3-C-NH2 CH3-S-OH CH2-S-OH F-S-OH

In each reaction, label the reactants as Lewis acids (electrophiles) or Lewis bases (nucleophiles). Use curved arrows to show the movement of electron pairs in the reactions. Draw in any nonbonding electrons to show how they participate in the reactions.

Problem 54SP In 1934, Edward A. Doisy of Washington University extracted 3000 lb of hog ovaries to isolate a few milligrams of pure estradiol, a potent female hormone. Doisy burned 5.00 mg of this precious sample in oxygen and found that 14.54 mg of CO2 and 3.97 mg of H2O were generated. (a) Determine the empirical formula of estradiol. (b) The molecular weight of estradiol was later determined to be 272. Determine the molecular formula of estradiol.

Problem 55SP The pKa of ascorbic acid (vitamin C, page 2) is 4.17, showing that it is slightly more acidic than acetic acid (CH3COOH,pKa 4.74). (a) Show the four different conjugate bases that would be formed by deprotonation of the four different OH groups in ascorbic acid. (b) Compare the stabilities of these four conjugate bases, and predict which OH group of ascorbic acid is the most acidic. (c) Compare the most stable conjugate base of ascorbic acid with the conjugate base of acetic acid, and suggest why these two compounds have similar acidities, even though ascorbic acid lacks the carboxylic acid (COOH) group.

Use electronegativities to predict the direction of the dipole moments of the following bonds. (a) \(C-C 1\) (b) \(C-O\) (c) \(C-N\) (d) \(C-S\) (e) \(C-B\) (f) \(N-C 1\) (g) \(N-O\) (h) \(N-S\) (i) \(N-B\) (j) \(B-C 1\) Equation Transcription: Text Transcription: C-C1 C-O C-N C-S C-B N-C1 N-O N-S N-B B-C1

Draw Lewis structures for the following compounds and ions, showing appropriate formal charges. (a) \({\left[\mathrm{CH}_{3} \mathrm{OH}_{2}\right]^{+}}\) (b) \(\mathrm{NH}_{4} \mathrm{Cl}\) (c) \(\left(\mathrm{CH}_{3}\right)_{4} \mathrm{NCl}\) (d) \(\mathrm{NaOCH}_{3}\) (e) \({ }^{+} \mathrm{CH}_{3}\) (f) \({ }^{-} \mathrm{CH}_{3}\) (g) \(\mathrm{NaBH}_{4}\) (h) \(\mathrm{NaBH}_{3} \mathrm{CN}\) (i) \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{O}-\mathrm{BF}_{3}\) (j) \({\left[\mathrm{HONH}_{3}\right]^{+}}\) (k) \(\mathrm{KOC}\left(\mathrm{CH}_{3}\right)_{3}\) (l) \({\left[\mathrm{H}_{2} \mathrm{C}=\mathrm{OH}\right]^{+}}\) Equation Transcription: Text Transcription: [CH_{3}OH_{2}]+ NH_{4}Cl (CH_{3})_{4}NCl NaOCH_{3} ^{+}CH_{3} ^{-}CH_{3} NaBH_{4} NaBH_{3}CN (CH_{3})_{2}O-BF_{3} [HONH_{3}]^+ KOC(CH_{3})_{3} [H_{2}C=OH]^+

Draw the important resonance forms for the following molecules and ions. (a) \(\mathrm{CO}_{3}^{2-}\) (b) \(\mathrm{NO}_{3}^{-}\) (c) \(\mathrm{NO}_{2}^{-}\) (d) \(\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}-\mathrm{CH}_{2}^{+}\) (e) \(\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}-\mathrm{CH}_{2}^{-}\) (f) \(\mathrm{SO}_{4}^{2-}\) (g) \({\left[\mathrm{CH}_{3} \mathrm{C}\left(\mathrm{OCH}_{3}\right)_{2}\right]^{+}}\) (h) \(\mathrm{B}(\mathrm{OH})_{3}\) Equation Transcription: Text Transcription: CO_{3}^{2-} NO_{3}^- NO_{2}^- H_{2}C=CH-CH_{2}^+ H_{2}C=CH-CH_{2}^- SO_{4}^{2-} [CH_{3}C(OCH_{3})2]^+ B(OH)_{3}

For each of the following compounds, draw the important resonance forms. Indicate which structures are major and minor contributors or whether they have the same energy. (a) \(\mathrm{H}_{2} \mathrm{CNN}\) Equation Transcription: Text Transcription: H_{2}CNN C=N=N :C-N{equiv}N: :C-ddot{N}=N:

Draw complete Lewis structures for the following condensed structural formulas. (a) \(\mathrm{CH}_{3}\left(\mathrm{CH}_{2}\right)_{3} \mathrm{CH}\left(\mathrm{CH}_{3}\right)_{2}\) (b) \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHCH}_{2} \mathrm{Cl}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COCN}\) (d) \(\mathrm{CH}_{2} \mathrm{CHCHO}\) (e) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCOCHCH}_{2}\) (f) \(\mathrm{CH}_{3} \mathrm{COCOOH}\) (g) \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2}\right)_{2} \mathrm{CO}\) (h) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{COH}\) Equation Transcription: Text Transcription: CH_{3}(CH_{2})_{3}CH(CH_{3})_{2} (CH_{3})_{2}CHCH_{2}Cl CH_{3}CH_{2}COCN CH_{2}CHCHO (CH_{3})_{3}CCOCHCH_{2} CH_{3}COCOOH (CH_{3}CH_{2})_{2}CO (CH_{3})_{3}COH