Organic Chemistry: Concepts and Applications - Headley Allan D. 2020

Bonding and Structure of Organic Compounds
End of Chapter Problems

1. 1.26 Write the ground state electronic configuration for each of the following atoms.

a) Carbon

b) Oxygen

c) Nitrogen

d) Fluorine

e) Sodium

f) Lithium

g) Neon

h) Beryllium

i) Helium

j) Boron

2. 1.27 How many valence electrons are there in each of the following atoms?

a) Carbon

b) Oxygen

c) Nitrogen

d) Hydrogen

e) Fluorine

f) Boron

g) Lithium

h) Sodium

i) Beryllium


3. 1.28 Give Lewis dot structures for the following molecules.

a) C2H6O

b) CH2Cl2

c) C2H7N

d) C3H6

e) CH3OH

f) CH3Cl

g) CH3SH

h) CS2

i) H2O2

j) N2H2

4. 1.29 Determine which of the following molecules is(are) polar or nonpolar?

a) O2

b) Cl2

c) N2

d) H2O

e) CO2

f) H2O2

g) HCl

h) NH3

i) H2S

j) CO

k) CH2Cl2

l) BF3

m) CF4



5. 1.30 List the following atoms in terms of increasing electronegative, i.e. the least electronegative first: Li; C; O; N; Na

6. 1.31 Draw the Lewis dot structures for the following compounds, showing appropriate formal charges.

a) NH4NCl

b) NaBH4

c) CH3NO2

d) CH4

e) HCN

f) CH3N

7. 1.32 For the molecule shown below, indicate: (a) the type of hybridized orbitals for each atom (except hydrogen); (b) the geometry around each atom; and (c) the number of unshared pair(s) of electrons on each atom.Image

8. 1.33 What is the geometry about the central atom of the following?

a) BH3    b) Image

9. 1.34 Which of the following compounds would you expect to have a covalent bond(s)? Explain your answer.

NaCl, KCl, CCl4, CaO

10. 1.35 Draw Lewis dot structures of each of the following molecules and use δ+ and δ where possible to show the polarity of each covalent bond in the following molecules.

a) CO2

b) N2

c) HCl

d) H2O

e) CH3OH

f) CH3F

g) NH3

h) CH2O



11. 1.36 Write Lewis dot structures for each of the following ions.

a) OH

b) CO32−

c) HCO3

d) NH2

e) CH3O

12. 1.37 Give Lewis dot structures of the following and determine the formal charge on the nitrogen and the oxygen atoms.

a) CH3NH3

b) HNO3

c) CH3NH2

d) H3O+

13. 1.38 What is the formal charge on the central atom of each of the species shown below?Image

14. 1.39 What are the molecular formulas for the following compounds?Image

15. 1.40 For the following molecules, give the approximate bond angles about each of the atoms indicated by an arrow and determine the type of hybridized orbitals used in bonding to the other atoms.Image

16. 1.41 Below are the resonance structures of an ion. Determine which is the major resonance contributor and explain your answer.Image

17. 1.42 For the molecules shown below, draw another resonance structure. Use curved arrows to indicate electron movement and include formal charges where appropriate.Image

18. 1.43 Using dotted lines to indicate intermolecular interactions, indicate the hydrogen bond formed for each of the following molecules.

a) CH3CH2NH2

b) CH3SH

c) HF

d) CH3CO2H

19. 1.44 Consider the molecular formulas shown below, then answer the following questions.

C2H6O

CH2Cl2

C2H7N

C3H6

1. For each molecule, draw Lewis dot structure(s). [Note: there may be more than one structure for each molecule.]

2. Using the partial charge notation (δ+ or δ), indicate the polarity of each covalent bond for each isomer that you have drawn.

3. Is the molecule that you have drawn capable of forming hydrogen bonds to water?

4. Use dotted lines (…) to indicate the hydrogen bonded structure that would exist between two molecules that you have drawn in question b.

20. 1.45 Even though the molecular weight of methanamine (CH3NH2) is approximately the same as that of methanol (CH3OH), the boiling point of methanol is greater than that of methanamine (65.0 °C vs. −6.3 °C). Briefly explain this observation.

21. 1.46 The molecular weight of CH3SH (methanethiol) is greater than that of methanol (CH3OH), yet the boiling point of methanethiol is 6 °C, compared to the boiling point of methanol which is 65.0 °C. Briefly explain this observation.

22. 1.47 Which of the following pairs of molecules has a higher boiling point? Explain your answer.Image

23. 1.48 For each of the following pairs of compounds, which has a higher boiling point? Explain your answer.Image

24. 1.49 Which of the following compounds have dipole moments greater than zero?

a) CH2Cl2

b) BF3

c) CF4

d) H2O

e) NH3