organic homework

HW 2 Total points 100 Answer the following questions: 1. Which two species act as bases in the acid-base reaction shown below?

A) 1 and 2 B) 3 and 4 C) 2 and 4 D) 1 and 3 E) 2 and 3 2.What is the conjugate acid of NH3? A) +NH3 B) -NH C) +NH4 D) -NH2 E) +NH2 3. What is the conjugate acid of HSO4-? What is the conjugate base of HSO4-? 4. Write the products of the following acid-base reaction. HCO2H + -NH2 → 5. If H2O has a pKa value of 15.7 and HF has a pKa value of 3.2, which is a stronger base, HO- or F-? Explain. 6. What base is formed in the following acid-base reaction?

A) CH2O B) CH3OH C) CH3SH2+ D) CH3S- E) H2O

7. What acid is formed in the following acid-base reaction?

A) CH2O B) CH3OH C) CH3SH2+ D) CH3S- E) H2O 8. Rank NH3, HF, and H2O in order of increasing acidity and explain your rationale. 9) Which of the following has the highest pKa? And Why? (No need to write the pKa Values - just expalin) A) CH3CH3 B) HC CH C) CH2 CH2 D) CH3OH E) CH3NH2 10) Draw a resonance contributor and the resonance hybrid for HOCO2-. 11) The structure of Lorazepam, a drug used for short-term anxiety, is shown below. Is the indicated lone pair localized or delocalized?

12) When a small amount of CH3(CH2)4CO2H (pKa ~4.8) is added to a separatory funnel that contains ether and water with a pH = 12.0, it is found mainly in the ________ layer as ________. A) ether; CH3(CH2)4CO2-

B) water; CH3(CH2)4CO2- C) ether; CH3(CH2)4CO2H D) water; CH3(CH2)4CO2H E) none of the above 13) H-A is an acid with a pKa = 4.5. Which of the following statements about an aqueous solution of H-A is true? A) At pH = 4.5, the solution contains much more H-A than A-. B) At pH = 4.5, the solution contains much more A- than H-A. C) At pH- 3.5, the solution contains about 90% A- and 10% H-A. D) At pH = 6.5, the solution contains about 80% A- and 20% H-A. E) At pH = 5.5, the solution contains about 90% A- and 10% H-A. 14) At what pH will the concentration of a compound with a pKa = 5.7 be 100 times greater in its acidic form than in its basic form? 15) HCN has a pKa = 9.1. What form of the compound, HCN or CN-, predominates in a solution with pH = 7.0 16) A buffer is used to maintain the pH of human blood at ~ 7.4. Which acid/base pair buffers the blood? A) H2O / HO-

B) H3O+ / H2O C) H2CO3 / HCO3-

D) NH4+ / NH3 E) HCl / Cl-