Organic Chemistry

58 CHAPTER 1 Electronic Structure and Bonding • Acids and Bases

59. a. Which of the indicated bonds in each molecule is shorter?
    b. Indicate the hybridization of the C, O, and N atoms in each of the molecules.
    
    
    1. 
       
       
       
       3. 
          
          
          
          5. 
             
          
          
          
          
       
       
       
       
    
    
    2. 
       
       
       
       4. 
          
       
       
       
       
    
    
    
    


60. For each of the following compounds, draw the form in which it will predominate at and

a. b. c.

61. Which of the following molecules have tetrahedral bond angles?


62. Do the hybridized carbons and the indicated atoms lie in the same plane?


63. Give the products of the following acid–base reactions, and indicate whether reactants or products are favored at equilibrium (use
    the values that are given in Section 1.17):

a. c.

b. d.

64. For each of the following molecules, indicate the hybridization of each carbon atom and give the approximate values of all the
    bond angles:
    a. b. c.


65. a. Estimate the value of each of the following acids without using a calculator (i.e., between 3 and 4, between 9 and 10, etc.):
    
    
    1. nitrous acid 4. hydrogen cyanide (HCN),
    
    
    2. nitric acid 5. formic acid (HCOOH),
    
    
    3. bicarbonate
       b. Determine the values, using a calculator.
       c. Which is the strongest acid?
    
    
    
    


66. a. List the following carboxylic acids in order of decreasing acidity:
    
    
    1. 
       
       
       
       2. 
          
          
          
          3. 
             
             
             
             4. 
                
             
             
             
             
          
          
          
          
       
       
       
       
    
    
    
    

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 a carboxylic acid?

67. Draw a Lewis structure for each of the following species:


68. 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):

a. CH 3 N 2 + b. CH 2 N 2 c. N 3 – d. N 2 O (arranged NNO)

CH 3 CHCH 2 COOH

Ka = 8.9 × 10 −^5

Cl

ClCH 2 CH 2 CH 2 COOH

Ka = 2.96 × 10 −^5

CH 3 CH 2 CHCOOH

Ka = 1.39 × 10 −^3

Cl

CH 3 CH 2 CH 2 COOH

Ka = 1.52 × 10 −^5

pKa

(HCO 3 - ), Ka=6.3* 10 -^11

(HNO 3 ), Ka= 22 Ka=2.0* 10 -^4

(HNO 2 ), Ka=4.0* 10 -^4 Ka=7.9* 10 -^10

pKa

CH 3 C‚CH CH 3 CH“CH 2 CH 3 CH 2 CH 3

CH 3 CH 2 OH + −NH 2 CH 3 CH 2 OH + HCl

O

CH 3 COH + CH 3 NH 2

O

CH 3 COH + CH 3 O−

pKa

CH 3

CH 3

CH 3

H

H

CH 2 CH 3

CC

CH 3

H

H

CH 3

CC

sp^2

H 2 O H 3 O+ +CH 3 BF 3 NH 3 +NH 4 – CH 3

pKa4.8 pKa11.0 pKa12.4

CH 3 CH 2 N CF 3 CH 2 OH

+

CH 3 COOH H 3

pH=3, pH=6, pH=10, pH=14:

CHC C H

H

H

C

O

CH 3 CCH 2 OH

C CHC C C

CH 3

CH 3

H

H

H

CH 3 CH CHC CH CH 3 NH CH 2 CH 2 N CHCH 3