Organic Chemistry 1

1. Draw the Lewis structure of acetic acid, CH3CO2H, clearly indicating all non-bonding pairs of electrons.

2. Even though nitrogen and phosphorus have the same number of valence electrons, nitrogen can only bond to chlorine four times forming NCl4+ but phosphorus can bond with chlorine five times forming PCl5. Explain.

3. Constitutional isomers differ in the ___.

4. Draw all the isomers of C4H9Br, using bond-line formulas.

5. Draw the Lewis structure of the nitrite ion, NO2–, clearly indicating resonance contributors as well as non-bonding pairs of electrons and formal charges, as relevant.

6. There are three fundamental rules that we use in writing electronic configurations for atoms and molecules. The configuration shown below (for oxygen) violates one of these rules. Which one?

7. When atomic orbitals of opposite phase overlap a(n) ___ molecular orbital is formed.

8. The molecule N2 does not show an absorption in an IR spectrum because the dipole moment of the molecule does not change with the absorption of IR energy.

9. All of the carbon-carbon bonds in ___ are equal to one and one-half bonds and have a bond length in between that of a single bond and a double bond with all of the bond angles at ___.

10. Unsaturated hydrocarbons may be distinguished from saturated hydrocarbons by the presence of one or more ___.

11. Draw all isomers of C6H14.

12. A polar covalent bond is one in which electrons are ___.

13. The ___ is defined as the product of the magnitude of the charge of a particle and the distance that separates them.

14. Carbon dioxide is non-polar, despite the fact that oxygen is much more electronegative than carbon. Briefly explain why, using relevant diagrams as appropriate to illustrate your answer.

15. Nitromethane is a polar molecule but contains 2 equal polar covalent bonds. Briefly explain why and draw a relevant 3-dimensional structure to show the overall dipole moment of the molecule.

16. Organic compounds are classified into chemical families on the basis of similarities in chemical properties; these similarities are primarily due to the presence of characteristic arrangements of atoms known as ___.

17. Draw all isomers of C6H12O that are aldehydes.

18. Draw all isomers of C5H10O that are ketones.

19. Draw all of the isomers of C5H9N that are nitriles.

20. Ethanol, C2H5OH, and propane, C3H8, have approximately the same molar mass, yet ethanol has a much higher boiling point. Briefly explain why.

21. Ethanol, C2H5OH, and dimethyl ether, CH3OCH3, have the same molar mass, yet ethanol has a much higher boiling point. Briefly explain why.

22. Sodium chloride, which is quite soluble in water, is not very soluble in hexane. Why

23. Explain why the compound shown is considered to be capable of being a soap (dissolving oily substances off of surfaces using water).

24. Examine the following IR spectrum, for substance Q (C7H14O2). Which oxygen containing functional group is most likely present in Q?

25. The molecule or ion that is formed when an acid loses its proton is called the ___.

26. When drawing mechanisms, chemists generally use curved arrows. The curved arrow begins at a(n) ___ rich area and points toward a(n) ___ deficient area.

27. The isomer of alanine shown below is one of the 20 naturally occurring amino acids that are used to make proteins. Amino acids like alanine exist at neutral acidity (pH = 7) in the following form:
What would be the structure of alanine if HCl(aq) was added to lower the pH = 1? What would be the structure of alanine if NaOH(aq) was added until the pH = 12?

29. Write an equation to show the reaction between ethanol, C2H5OH and methyllithium, CH3Li. Draw all non-bonding electrons and show electron flow with curved arrows.

30. Write an equation that shows the reaction between acetic acid (CH3COOH) and triethylamine (CH3CH2)3N. Draw all non-bonding lone electron pairs and show the electron flow with curved arrows.

31. Why do water-insoluble carboxylic acids dissolve in aqueous sodium hydroxide?

32. Briefly, but clearly, explain why the –OH hydrogen in acetic acid (CH3CO2H) is more acidic than in ethanol (C2H5OH).

33. Draw an arrow pushing mechanism to illustrate the formation of t-butyl bromide from t-butanol and draw in the necessary intermediates and products formed.

34. You are planning to carry out a reaction between propyne, CH3C≡CH and sodium amide, NaNH2. You also need to choose an appropriate solvent for carrying out the reaction. Would ethanol be suitable for this purpose? Explain your rationale clearly.