Chapter 3.3, Problem 12CC

O2- + H2O——- Complete the acid base reaction.

The pH of the given solution of lactic acid and lactate is 5.24. Calculate the pKa of lactic acid, when the concentration of lactic acid and lactate are 0.024 M and 0.087 M respectively.

Note these acronyms: HOAC = Acetic Acid; NaOAc = Sodium Acetate; THE = tetrahydrofuran Ph = Phenyl = C6H5; DMSO = Dimethyl Sulfoxide, H3C-O-H = methanol, Zn = Zinc, D = heavy Hydrogen (1 proton and 1 neutron). Acetone = Acetic Acid = THF= Ph= H3C `CH3 H3C HO. 1. Write the products of the following reactions. If there is no reaction write NR. For full credit clearly indicate cis or trans relationships in cyclic compounds, where appropriate. + Cl,, w ater s ol vent CH3 + Br,, water solvent -CH, + Br2, water solvent +к MnO 4, Кон, cold

Acetic acid (pKa = 4.75) is contained in vinegar. What is the pKb of the conjugate base of acetic acid, the acetate anion?

8 (Chemical Connections 19C) Once it has been opened, and particularly if it has been left open to the air, a bottle of aspirin may develop a vinegar-like odor. Explain how this might happen.

18-31 Formic acid is one of the components responsible for the sting of biting ants and is injected under the skin by bee and wasp stings. The pain can be relieved by rubbing the area of the sting with a paste of baking soda (NaHCO3) and water, which neutralizes the acid. Write an equation for this reaction.

Lactic acid, CH3CH(OH)COOH, is a weak monoprotic acid with a melting point of 53 C. It exists as two enantiomers (Sec. 7-2f) that have slightly different Ka values. The D form has a Ka of 1.5 104 and the L form has a Ka of 1.6 104. The D form is synthesized by some bacteria. The L form is produced in muscle cells during anaerobic metabolism in which glucose molecules are broken down into lactic acid and molecules of adenosine triphosphate (ATP) are formed. When lactic acid builds up too rapidly in muscle tissue, severe pain results. (a) Which form of lactic acid (D or L) is the stronger acid? Explain your answer. (b) Determine the pKa that would be measured for a 50:50 mixture of the two forms of lactic acid in aqueous solution, pKa = log Ka (c) A solution of D-lactic acid is prepared. Use HL as a general formula for lactic acid, and write the equation for the ionization of lactic acid in water. (d) If 0.100-M solutions of these two acids (D and L) were prepared, calculate what the pH of each solution would be. (e) Before any lactic acid dissolves in the water, what reaction determines the pH? (f) Calculate the pH of a solution made by dissolving 4.46 g D-lactic acid in 500. mL of water. (g) Calculate the volume (mL) of 1.15-M NaOH(aq) required to completely neutralize 4.46 g of pure lactic acid. (h) Calculate the pH of the solution when exactly enough NaOH was added to neutralize all of the lactic acid for (i) the D form; (ii) the L form; and (iii) a 50:50 mixture of the two forms.

18-30 Complete the equations for these acid-base reactions.

What is the conjugate acid of H2C6H7O5 -1aq2? What is its conjugate base?